Networking 4z29e

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PROJECT REPORT ON NETWORKING

ANAND SUNDAR TIWARI R09111261 B.Tech Computer Science 7th Semester Under the guidance of MR. Suraj Singh (Branch Manager/Trainer in CETPA info tech )

DEPARTMENT OF COMPUTER SCIENCE ENGINEERING COLLEGE OF ENGINEERING TEERTHANKER MAHAVEER UNIVERSITY MORADABAD – 244001 2012

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A Report on Industrial Training NETWORKING Submitted in Partial fulfillment of the requirement for the degree of

BACHELOR OF TECHNOLOGY In COMPUTER SCIENCE & ENGINEERING by ANAND SUNDAR TIWARI (R09111261) Under the guidance of MR. SURAJ SINGH (Branch Manager/Trainer in CETPA info tech )

COLLEGE OF ENGINEERING TEERTHANKER MAHAVEER UNIVERSITY N.H.24, BAGARPUR, MORADABAD – 244001 2012

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INTRODUCTION This project report pertains to six week industrial training that I had underwent at CETPA, Roorkee as part of curriculum of degree in Bachelor of technology in Computer Science Engineering as required by Teerthanker Mahaveer University College of engineering . I learnt a lot from professional managers and skilled engineers. I had a great learning experience as trainee in this firm. I learnt a lot about how different networks are controlled in the industry or any department with the help of networking processes, under MCSE. I have learnt about different type of servers like DH Server, DNS Server, and NAT Server. Also I have learnt how to control the LAN and MAN networks under MCSE (Microsoft Certified System Engineers) and how to control MAN and WAN network sunder CCNA (CISCO Certified System Engineers).Justification cannot be done to whatever I have learnt in these six week within a few pages but I have still tried my best to cover as much as possible in this report. In this report I have tried to sum up the technical knowledge I have gained in my six week of training.

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2. NETWORKING

2.1 Introduction to Networking Networking is a practice of linking of two or more computing devices such as PCs, printers, faxes etc., with each other Connection between two devices is through physical media or logical media to share information, data and resources. Networks are made with the hardware and software

Cable/media Fig 1: computer network

2.1.1 Models of Networking Model means the connectivity of two computers. We have many types of networking models. (i) (ii) (iii)

Client – Server Model Peer to Peer Model (Workgroup Model) Domain Model

(i) Client –Server Model In a Client server model we have one server and many clients. A Client can share the resources of server, but a server cannot share the resources on clients. On the point of view of it‘s very easy to control the network because we combine with the server also at security point of view. It is very useful because it uses level security in which s have to only one to share the resources. (ii) Peer to Peer Model (Workgroup Model) In Peer to Peer networking model all computers are in equal status, that is we cannot manage centralization, istration security. In Peer to Per networking client use operating system like Window 98, Window XP, Window 2000, Window Vista.

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(iii) Domain Model It is a mixture of client server and peer-to-peer model. In this clients can share their resources as peer-to-peer but with the permission of the server as in client server model therefore it is commonly used model because in this security is more as we can put restriction on both server and clients Difference between Workgroup & Domain Table 1 Workgroup

Domain

1. It is a peer to peer networking model.

1.

2. There is no client and no server. All the computers are in equal status.

2.

3. This model is recommended for small networks, up to 10 computers.

3.

4. There is no centralized istrated separately.

4.

5. In this model, low grade OS like2000/XP professional, WIN 98 etc. can be used.

5. 6.

6. ‘s s are created in each PC and are called as Local s.

It is a server based networking model. There is a centralized dedicated server computer called domain cont roller which controls all other computers called clients. This model is recommended for large networks. There is centralized istration and each PC can be istrated and managed from the server. In this model high grade OS like WIN2000/2003 Server can be used. ‘s s are created on the server side and are called Domain s.

2.1.2 Categories of network Networks can be categorized as per geographical area to be covered by thenetwork. Computer network are divided into four categories includes: Local Area Network (LAN), Campus Area Network (CAN), Metropolitan Area Network (MAN) and Wide Area Network (WAN). 2.1.2.1 Local Area Network (LAN) LAN is a computer network that is used to connect computers and work station to share data and resources such as printers or faxes. LAN is restricted to a small area such as home, office or college. Devices used in LAN are : HUB and switch. Media for LAN is UTP cables. Figure 1.2 shows how all work stations, server and printer are interconnected with the help of the network device

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Fig 2: Local Area Network Types of LAN In LANs, data can be transferred using techniques like token ing. As per techniques used for data sharing, LANS are classified into Ethernet, Token Bus, Token Ring and Fiber Distributed Data Interface (FDDI).Figure 3.3 shows LAN classification.

Fig 3: LAN classification Advantages of LAN a) Provides communication in smaller networks, easy to install and configure. b) many s can share data or network elements at the same time which results in fast work.

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Disadvantages of LAN a) limited number of computers are connected in a LAN. b) LAN cannot cover large area. c) Network performance degrades as the number of s exceeds.

2.1.2.2 Campus Area Network (CAN) Campus Area Network is a computer network made up of two or more LANs within a limited area. It can cover many buildings in an area. The main feature of CAN is that all of the computers which are connected together have somerelationshi p to each other e.g. different buildings in a campus can be connected using different CAN. It will help to interconnect academic departments, library and computer laboratories. CAN is larger than LAN but smaller than WAN. Figure 4 shows a CAN network.

Fig 4: Campus Area Network Devices used in CAN are: HUB, Switch, Layer-3 switch, Access Point .And the media used for CAN is unshielded twisted pair of cables and Fiber Optics Cable.

2.1.2.3 Metropolitan Area Network (MAN) MAN is the interconnection of networks in a city. MAN is not owned by a single organization. It acts as a high speed network to allow sharing resources within acuity. MAN can also be formed by connecting remote LANs through telephone lines or radio links. MAN s data and voice transmission. The best example of MAN is cable T.V network in a city.

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Fig 5: Metropolitan Area Network 2.1.2.4 Wide Area Network (WAN) WAN covers a wide geographical area which includes multiple computers or LANs. It connects computer networks through public networks like, telephone system, microwave, satellite link or leased line. Most of the WANs use leased lines for internet access as they provide faster data transfer. WAN helps an organization to establish network between all its departments and offices located in the same or different cities. It also enables communication between the organization and rest world. Devices used in WAN is only Router.

2.2 IP ADDRESSES and MAC Addresses It is also called as logical addresses. IP is a 32 bit long and it is divided into 4octets and dot (.) is used to separate one octet from another. It is represented in the form of decimals. There are two versions of IP addresses:

- IPv4 - IPv6 Table 2 Comparison between IPv4 and IPv6 IPv4

IPv6

1. It is 32 bit long.

1.

It is 128 bit long.

2. It is divided into 4 octets.

2.

It is divided into 16 octets.

3.

IPv6 doesn‘t broadcasting, it perfor ms multicasting and unicasting.

4.

Ipv6 doesn‘t classes.

5.

IPv6 is in hexadecimal form

3. Ipv4 performs broadcasting, multicasting and unicasting. 4. IPv4 is divided into 5 classes : A to E. IPv4 is decimal form.

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2.2.1 IP Address Classes IP address is a 32 bit address. It is divided into various classes namely Class A, Class B, Class C, Class D and Class E. T/IP defines Class D for experimental purpose.T /IP address contains two addresses embedded within one IP address; Network address and host address as shown in figure 3

NETWORK ADDRESS

HOST ADDRESS

0 bits

31 bits

Class A consists of 8-bit network ID and 24-bit host ID. Class B consists of 16- bit network ID and 16-bit of host ID. And Class C consists of 24-bit of network ID and 8-bit of host ID. Address Classes Table 3: Address Classes

Address Class

Starting Bits

Range of first octet

Mask Value

Valid Hosts

Class A

0

1 to 27

255.0.0.0

256*256*256-2 = 16,777,214

Class B

10

128 to 191

255.255.0.0

256*2562=65,534

Class C

110

192 to 223

255.255.255.0

256-2

Class D

1110

224 to 239

Reserved for multicasting

Class E

1111

240 to 255

Reserved for research and development

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2.2.1.1 How to Assign IP Address to Computer An IP address assigned to a computer may either be permanent address or address that is assigned to a computer on a time lease or for temporary basis. Hence, the address granted to computers is divided into two categories Dynamic IP addresses and Static addresses. Dynamic IP Addresses Dynamic IP addresses are assigned to the devices that require temporaryconnectivity to the network or non-permanent devices such as portable computer. The most common protocol used for asg Dynamic IP address is DH also called. Dynamic Host Configuration Protocol. The DH grants IP address to the computer on lease basis. Static IP Addresses Static IP addresses are assigned to the device on the network whose existence in the network remains for a longer duration. These static IP addresses are semi-permanent addresses which remain allocated to a specific device for longer time e.g. Server. 3.2.1.2 How to Configure IP Address in window 2003  Right click on My Network Place- properties  Right click on working LAN card – properties  Select internet protocol (T/IP) – properties  Tick on – Use the following IP address – now fill the IP address e.g. 10.0.0.1  Tick on- Use the following DNS sever address  Fill the preferred DNS server – 10.0.0.1  Ok  Close Now check the connectivity of computer with itself with command. Start-run-cmd-ping 10.0.0.1 2.2.2 MAC Addressing MAC address is a hardware address that is embedded in the NIC card. It is also known as hardware address or physical address. Every NIC card has a unique MAC address assigned by IEEE. MAC address is used to identify the nodes at lower levels of OSI model. The MAC address operates at the data link layer of the OSI model. MAC address is a 12 digit hexadecimal number (48 bit address). It is made up of numbers from 0-9 or a letter from A-F. MAC address can be written in any one of the formats:



MM:MM:MM:SS:SS:SS

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To identify the MAC address in window :    

Click Start – Run Enter cmd in the open text book Type ipconfig /all Press Enter

The 12 digit MAC address will be shown as say 00:11:11:EA:8D:F6

2.3.3 NETWORKING MEDIA To do networking we need to use some type of media. There are many types of media. (i) (ii) (iii) (iv) (v)

Coaxial Cable Fiber optic cable Twisted Pair of Cables Micro-wave satellite

Coaxial Cable Coaxial cable consists of an insulated copper conductor surrounded by a tube shaped copper braid outer copper tune and the inner conductor have the same axis of curvature hence it called coaxial cable. It is basically of two types: (i) (ii)

Base Band Cable (RG-59) Broad Band Cable (RG-58)

We used Base Band signal cable in Networking of Computers; It is so called because it carries single frequency. Its speed is 10 Mbps and impedance is 50 Ω. Whereas Broad. Band Cables carries multiple frequencies. Connector used for Coaxial cable is BNC (British Novel Connector) connector. ARC net uses RG-62 coaxial cable. It has an impedance of 93 Ω and has a comparatively lesser attenuation, hence yield greater distances. These cables are expensive and provide high propagation factor. Fiber Optical Cable Fiber optic cable consists of a very fine fiber made from two types of glass, one for thinner core and the other for the outer layer. Here signal is transmitted in the form of light. Different varieties of fiber optics is used depending on the size of the network. Single mode fiber optics is used for networks spanning longer distance. Fiber Optics has lower propagation factor than coaxial cable. It is a costly but more secure transmission media. Twisted Pair Cable There are two wires, which are twisted with each other to avoid EMI (Electromagnetic Induction).these cables are easy to terminate. However they have a slightly higher value of attenuation value and hence have limited distance covering capacity.

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Connector used for Twisted Pair of Cable is (ed Jack) RJ-45 and RJ-11. There are two types of twisted pair of cables: 

STP (Shielded Twisted Pair): In this an extra wire which is called shielded wire is wrapped over the inner cover which holds copper in pairs. This protection is used to protect signal from external noise.



UTP (Unshielded Twisted Pair) In this type of wire no shielded cover is there for extra protection from noise. There are different categories of UTP cables.

Categories of UTP Cables Table 4: Category and Speed of UTP cables Category

Speed

CAT-1

56 Kbps

CAT-2

4Mbps

CAT-3

10 Mbps

CAT-4

16-20 Mbps

CAT-5

100 Mbps

CAT-6

1 Gbps

CAT-7

1 Gbps

2.3.1 Ethernet Cabling There are three types of Ethernet cables:  Straight cable  Crossover cable  Rolled cable 2.3.1.1 Straight cable It is used when we have to connect  PC To Switch  PC to Hub  Hub to Router  Switch to Router

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Color Coding for straight Cable TABLE 5

568A (one end)

568B (other end)

Green/white Green Orange/white Blue Blue/white Orange Brown/white Brown

Green/white Green Orange/white Blue Blue/white Orange Brown/white Brown

(one end)

(other end)

Green/white Green Orange/white Blue Blue/white Orange Brown/white Brown

Green/white Green Orange/white Blue Blue/white Orange Brown/white Brown

3.3.1.2 Crossover Cable It is used when we have to connect:  PC to PC  Hub to Hub  Switch to Switch  Router to Router  PC to Router  Hub to Switch Color Coding for Crossover cable Table 6

Color Coding for Crossover cable (one end)

Orange/white Orange Green/white Blue Blue/white Green Brown/white Brown

(other end)

Green/white Green Orange/white Blue Blue/white Green Brown/white Brown

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2.3.1.3 Rollover Cable Rollover cable isn‘t used to connect any Ethernet connections together, but Rollover cable can be used to connect a host to a router console serial communication (com) port. NOTE: Straight cable and Cross cables are used for data transfer but Rollover cables are not used for data transfer. There are two methods for manufacturing Rollover cables: Table 7 Color Coding for Rollover Cable

568A (one end) Green/white Green Orange/white Blue Blue/white Orange Brown/white Brown

568B (other end)

Green/white Brown/white Orange Blue/white Blue Orange/white Green Green/white

(one end) Orange/white Orange Green/white Blue Blue/white Green Brown/white Brown

(other end) Brown Brown/white Green Blue/white Blue Green/white Orange Orange/white

2.4 OPERATING SYSTEM 2.4.1 Types of Operating Systems (i) (ii)

DOS (Desktop Operating System) NOS (Network Operating System)

Table 8: Operating Systems DOS It is a desktop operating system. It is used in small networks. In this OS, there is less security. In this OS, all computers are clients. 5. In this OS, MS-DOS, GUI packageWin3.1, Win 95, Win 98, Win ME comes 1. 2. 3. 4.

NOS It is a network operating system. It is used for large networks. In this OS, there is more security. In this OS, there are servers and clients. 5. In this OS Win NT, Win 2000, Win2003, LINUX, UNIX, Novell and MAC comes. 1. 2. 3. 4.

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2.4.1.1 Introduction to Window 2003 Server Window server 2003 (also referred to as WIN 2k3) is a server operating system produced by Microsoft. Introduced in 24thApril 2003 as the successor to window 2000 server, it is considered by Microsoft to be the corner stone of its window server system line of business server products. An update version Window Server 2003 R2 was released manufacturing on 6th Dec, 2005. Its successor window 2008 was released on 4th Feb. 2008. According to Microsoft, window server2003 is more scalable and delivers better performance than its predecessor window 2000. Features of Window 2003         

A significant improved version of Internet Information Service (IIS) Increased default security over previous version due to the built in firewall and having most services disabled by default. Manage your server-a role management istrative tools that allow an to choose what functionality the server should provide. Improvement to Active Directory. Improvement to Group Policy handling and istration. Provides a Backup system to restore lost files. Improved disk management, including the ability to Backup from shadows of files, allowing the Backup of open files. Improved security and command line tools which are part of Microsoft initiative to bring a complete command shell to the next version of window. for a hard based ―Watch Dog Timer‖, which can restart the server if the operating system does not suspend within a certain amount of time.

Removed Features 

The ability of creating server disk automated system recovery (ASR) is used instead.

Edition of Window 2003 Window server 2003 comes in a number of editions, each targeted towards a particular size and type of business. In general, all variant of window server 2003 Have the ability to share files and printers, act as application server and hostmessage queue, provide email services, authenticate s, act as an X.509certific ate server, provide LDAP (Light Weight Directory Access Protocol) services, serve streaming media, and to perform other server-oriented functions.

2.5 DNS SERVER DNS stands for domain name system. DNS system is a standard technology for managing the names of websites and other internet domains. DNS techniques allows you to

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type names into your web browser like computer networking, about computer and allow your computer to automatically find that address on internet. DNS is the resolution mechanism used by Window Server 2003 clients to find other computers and services running on those computers for computers in a window 2003 network infrastructure to talk to one another, one of the key ingredients is the DNS server .Host name alone do not communicate globally but communicate locally, but if domain name is added along with it then the host name can communicate globally. DNS is use for name reservation i.e. to convert IP address to host name and host name to IP address or the function of DNS is tore solve host name such as www.yahoo.comto an IP address. identify only friendly name and all computers and technologies identify IP address and MAC addressing is use to solve this problem because DNS is used to convert host name FQDN (fully qualified domain name) to IP address and IP address to host name.

2.5.1 PARTS OF DNS SYSTEM 1. 2. 3. 4. 5. 6.

Host Name Domain name FQDN DNS Server Namespace DNS Server

2.5.1.1 HOST NAME Host name is a computer name and is also called is NetBIOS (network basic Input/ output system) name. NetBIOS is actually an application layer protocol that can use the transport services of T/ IP when used in routed network. A NetBIOS name is16- byte addresses that identify a NetBIOS resource on the network. 3.5.1.2 DOMAIN NAME Domain name is used to identifies the internet site one can identifies the location without having to the IP address of every location e.g. yahoo.com or gmail.com. 2.5.1.3 FQDN FQDN means fully qualified domain name which represents a hostname appended to the parent name space in hierarchy. Also in fully qualified domain name different levels of namespace are visualize as in fig below this hierarchy is visualized─ the root level namespace, top─ level domain, and so on, in use throughout the internet today. Left

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most portion of the FQDN is the host portion of the name. A host name is alias we give to an IP address.

Fig 6: to find location of a computer using FQDN FQDN is a unique name in the computer on the network. We can identify host id and location of a computer as in fig above. Suppose we want to find location of pc1 with IP address 20.0.0.1, which is in lab2, 2nd floor in the organization center. The FQDN for this is Pc1.row3.lab2.floor2.center.com But this address is very lengthy to locate pc1 so to simplify this we use ―c name ―technique as: Pc1.center.com=20.0.0.1 2.5.1.4 Domain Namespace DNS operates in what is known as DNS namespace. The DNS namespace is anorgani zed, hierarchical division of DNS names. Domain namespace enable s to easilylocate the network services and resources. The domain namespace include the rootdom ain, the top level domain of the organization and organize this domain in a hierarchical tree structure. Namespace works on the hierarchical tree structure of root domain. There are total 13 root domain working in the internet, they are A, B, C, D, E, F, G, H, I, J, K, L and M. There is one root domain, which acts as the starting point of the fully qualified domain names. This root domain is designated with a dot (.). Fig 6.2 shows the tree structure or domain namespace.

Fig 7: Tree structure or Domain Namespace

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2.5.1.5 DNS server Any computer providing domain namespace is a DNS server. DNS server is used to convert host name FQDN into IP address and IP address into host name FQDN. To store the name-to-IP-addresses mappings so crucial to network communication, name server uses zone files. 2.5.2 DNS Zone Zone is the part of DNS database that contain record of domain or multiple domain. If the domains represents logical division of the DNS namespace, zones represents the physical separation of the DNS namespace. In other words information about records of the resources within DNS domain is stored in a zone files, and this zone files exist on hard drive of server. Zone files are divided into one of two basic types:  

Forward lookup zone: Provides host-name-to-IP-address resolution. Reverse lookup zone : Provides IP-address-to-host-name resolution

3.5.2.1 Resource record stored in a zone file Each record stored in a zone file has a specific purpose. Some of the records set the behavior of the name server, others have the job of resolving a host name or service into an IP table. (i)

NS(Name server) : These specify the name servers that are authoritative for a given portion of DNS namespace. These records are essential when DNS servers are performing iterative queries to perform name resolution.

(ii)

SOA (Start of Authority ): This resource record indicates the name of origin for the zone contains the name of the server that is the primary source for information about the zone. The information in an SOA record affect how often transfer of the zone are done between servers authoritative for the zone. It is also used to store other properties such as version information and timings that affect zone renewal or expiration.

(iii)

CNAME (Canonical Name): CNAME can be used to assign multiple names of a single IP address. For example, the server hosting the site www.abc.comis probably not named www, but a CNAME record exist resolution of www to an IP address all the

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same. The CNAME record actually points not to an IP address, but to an existing A record in the zone. 2.5.2.2 Steps to Install and configure DNS server  Start → control → add and remove program  Add remove window components  Select networking services and click on detail button  Check box DNS Server  Ok and Finish 2.5.2.3 Creating a Forward Lookup Zone  Statically fill the IP address  Start → tools  DNS → right click on forward lookup zone  New zone → next  Select primary zone → next  Enter zone name (abc.com) → next  Tick Allow both secure and non secure update and secure dynamic update  Next → next  Now click on created zone (abc.com)  new host → enter host name for global level (i.e by entering www) fill IP address of the server , click and add button  enter another host name, a blank host with same IP i.e. do not fill its host name steps to change SOA and NS records  Right click on SOA records → properties  Fill primary server e.g. (www.abc.com)→ responsible person.  host master.abc.com → apply→ ok  right click on NS records  click on add button → enter FQDN → www.abc.com  resolve → ok → apply → ok Now go to start menu → ping abc.com On Client Side → To access DNS server fill IP address of server then use ping command. e.g. ping www.abc.com 2.5.2.3 Creating a Reverse Lookup Zone    

Right click on reverse lookup zone New zone→ next→ select primary zone→ next fill → Network ID→ next→ next Select allow both non secure and non secure dynamic updates.

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   

Finish Right click on created reverse zone→ new pointer enter host IP number e.g. (50.0.0.50) enter FQDN (www.chd.com)

3.5.2.4 Some DNS Commands (i) c : >tracertwww.yahoo.com command is used to check the path , a data packet follow from one router to another router. (ii) c:>nslookup command display the domain name with IP (works only when reverse lookup zone is set up). (iii) c:>ipconfig /all This command display FQDN, IP address, MAC address. (iv) c:>ipconfig /flushdns This command flush or clear all the information in the cache that is retrieved from DNS server. (v) c:>ipconfig /displaydns Display the current contents or entries in the cache. (vi) c:>ip config / any DNS name

2.6 DH SERVER DH (Dynamic Host Configuration Protocol) is a protocol that allocates IP address to computer on a network. DH centralized the management of IP address allocation and reduces human error associated with manual IP configuration. DH server supplies all the necessary networking parameters. Two things are always handed out as a part of DH configuration: IP address and subnet mask. Further DH will frequentlyconfigure clients with optional values, such as a default gateway, DNS server address , and the address of a Window Internet Naming Server, if one is present. Scenario showing DH server IP address allocation. 2.6.1 Working of DH Server (i) (ii) (iii) (iv)

DH Scope DH Super Scope Exclusion IP Range DH Lease Time

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(v)

IP Reservation

DH Scope Scope having the range of IP address for providing dynamic IP address to other computer. A group of IP address within a scope is called as DH scope. DH Super Scope A super scope is used to combine two or more scopes each serving different subnets, and can make the istration of several scopes on window 2003 DH server more manageable. Using super scope you can group multiple scopes as a single istrative. Entity that allows the client to lease from either one. With this feature, a DH server can: •

• •

DH clients on a single physical network segment where multiplelogical IP networks are used. When more than one logical IP network is used on each physical subnet or network, such configuration is called multi nets. DH clients located on the far side of DH and BOOTP relay agent. In multinet configuration, DH super scope can be used to group and activate individual scope ranges of IP addresses used on your network. In this way , a DH server computer can activate and provide leases from more than one scope to clients on a single physical network.

Exclusion IP range If you want to reserve some IP for any computer i.e. if we want that from the series of 192.168.0.2 to 192.168.0.100 if we want that a series of IP addresses must not be assigned automatically then at can be done using exclusive IP range. DH Leased Time DH lease time is validity of IP address. By default DH lease time is 8 daysminimum,1 day maximum 999 days, 23 hours to 53 day . Within 8 days:-After 80% of day clients demand new IP sometimes server refuse the client request. After 87.5% of days it will retry, and if the server did not give the new IP address then the client will receive APIPA address (Automatic Private IP Address).When a DH client is unable to locate a DH server, the client picks out a random IP address from the private APIPA address range of 169.254.*.*, with a subnet mask of 255.255.0.0. The 169.254.*.* IP range is private because that network number is not in use on the internet, it is random because the client generates an arbitrary host number for that network. The significance of APIPA is that DH client computers that cannot find a DH server can still be assigned an IP address and communicate with other computer son the same subnet mask that also cannot find DH server. It allows communication. when DH server is down or just plain not there. Note that APIPA does not assign a default gateway, and therefore it cannot communicate with any computer that lives on the other side of a router.

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IP Reservation There are some DH clients that you want to be the DH clients, but you will also want to make sure that they get same IP address every time. This can be done by statically filling the IP address. We can reserve IP address with the help of MAC address for a particular computer. 2.6.2 Installation Steps of DH Server • • • • •

start→ control add and remove program→ add and remove window components select networking services and click on detail button check box of DH server ok→ finish

2.6.2.1 Steps To Configure DH Server • • • • • • •

start→ program→ istrative tool select DH create new scope in action menu→ new scope → next give scope name → next give IP address range → next add exclusion name→ next check lease duration→ next→ finish

After DH server is configured, it is required to be authorized and DH scope should be active. For that select DH server and click on authorize in action menu .Then right click on scope name and click on active.

2.6.2.2 On Client Side • • • •

Go to LAN card properties → select T/IP protocol→ properties Select obtain IP address automatically Go to command prompt (cmd) Give command

2.6.2.3 Backup of DH Server We can take backup of all the configuration in DH server with the help of ist rator. Backup means to export the DH database to another system, as it is helpful in case due to any reason our data is corrupted or deleted, we can take our database from the place where it is stored. Steps of taking backup: • •

Stop the DH server and disable the DH server services Copy the DH server directory to a temporary location, say pen drive or on a new DH server.

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2.6.3 DH Relay Agent The DH relay agent is a software that listen DH discover packet and forward to DH server. In window 2003 server system the DH relay agent can be enabled as a part of Routing and Remote Access (RRAS). 2.6.3.1 Steps to Configure DH Relay Agent • • • • • • • • • •

Set the network, fill the IP address and select two LAN cards Open Routing and Remote Access → enable Routing and Remote Access Right click on general new routing protocols Select DH relay agent New interface Select LAN card which is to be connected to the cross cable i.e. L1 Ok Right click on relay agent → properties Enter IP address of DH server Add → apply → ok

2.7 ACTIVE DIRECTORY With the release of Windows 2000, Microsoft introduced Active Directory, a scalable, robust directory service. Active Directory is used to create server based networking. Active Directory‘s job is to store and make available a Directory database i.e. information about the , its class, name, address, mails, phone numbers, location. Active Directory is a technology created by Microsoft that provides a variety of network services like Directory Services, DNS based naming and other network informati on. Active Directory also allows to assign policies, deploysoftware and apply critical updates to an organizations. Active Directory was previewed in 1999, released first with window 2000 server edition and revised to extend functionally and improve istration in Window 2003. Additional improvements were made in Window server 2003 and Window server 2008.The fundamental building block of Microsoft‘s Directory services continues to be a domain. A domain is logically grouping of network resources, including shares, printers, groups and s s. The represents the individual to domain, and allows for different type of access and different types of tasks. Every s is unique. It has uniqueness of the that allows to control access for every member of domain. There are two types of ‘s s: local and domain . Local s are maintained in the local database of a computer and cannot be used to grant access to network resources. Local s are primarily used to ister a computer or to allow several people to share a single computer that is not a member of a domain. Whereas domain s s are much more widely used in organizations that local s because they allow for central istration and can log onto any computer in the domain. Domain ‘s s are stored in Active Directory.

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2.7.1 Active Directory Services A computer network can be divided logically into two networking models.  

Workgroup Domain

Difference between Workgroup and Domain Table 9

Workgroup

Domain

1. It is a peer-to-peer networking model.

1. It is a server based networking model.

2. There is no client and no server. All computers are in equal status.

2. There is a centralized dedicated server computer called domain controller (DC)which controls all other computers called clients.

3. This model is recommended for small networks (upto 10 pcs).

3. This model is recommended for large networks. 4. There is no centralized istration and each PC is istrated separately. 5. In this model, low grade operating system like 2000/xp professional, win 98 etc can be used.

4. There is centralized istration and each PC can be istrated and managed from the server. 5. In this model high grade operating system, like win2000/2003 server are used.

6. Workgroup can be given names like sales, HR, s etc.

6. Domain can also give names likeabc.com, xyz.com etc.

7. ‘s s are created in each PC and are called as ―Local ‘s‖.

7. s s are created on sever side DC and are called as ‖Domain ‘s‖.

Active Directory uses domain to hold objects, each domain has security boundary. s must authenticate to the domain in which their s resides before they can access resources, such as a shared folders. Active Directory also links relateddomains in a hierarchical structure and s can access resources in any of the domain in which their resides. The hierarchical structures of related domain are called a tree, and all domains in the tree share the same Domain Name System (DNS) name space. All the domains and the trees in a single organization are called a forest. All domains in the forest share same schema.

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2.7.1.1 Types of Domain  Domain Forest  Domain tree  Organization unit Domain Forest A forest is created when window 2k3 server computer is configured as a domaincontr oller. A forest is a collection of multiple domain link together and relationship between the domains. Domain Tree A domain tree is made up when there is a parent child relationship between the domain in the forest. The child domain includes the complete parent domain name. a tree is a set of two or more domains sharing common namespace e.g. we can create a parent domain and then child domain like mail.yahoo.com; where mail- child domain, yahoo- parent domain.

Fig 8: Structure of domain forest and domain tree Organization Unit (OU) Organization unit is the smallest unit in a domain network that can contain s, computer groups, shared folders, printers and group policy object in simple words. OU means department like sale department, s department like sales, s in a company OU can be used to apply different security policies to computer and s indifferent department. OU also helps in dividing istration among different of managing only computer and s of sales department.

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3.7.1.2 Types of Domain Controller (i) (ii) (iii)

PDC : Primary domain controller ADC : Additional domain controller BDC : Backup domain controller

Primary Domain Controller (PDC) This is the first domain controller, in this domain all entries are created in it like s , group policy, Organization unit etc. All FSMO roles are done in PDC. Additional Domain Controller (ADC) It is a domain network, it is important to have more than one DC so that if one DC fails, the other DC will continue serving the client. There is also load balancing of Active Directory Service if we have more than one DC. The first DC we create is simply called PDC and if we create an extra DC then that DC is known as ADC. ADC has same configuration of AD as primary domain controller . All domain controllers in a domain networking are masters. We can make a change in the active directory of any domain controller and that change is replicated to all other domain controllers. Replication takes place among all the domain controllers and it is controlled automatically. If we create a in the first domain controller, it is automatically created in the ADC because of replication. All the domain controllers in the domain networking are peers and this model is called as multi- master model.

Fig 9: Multi-Master Model 2.7.1.3 Requirements of Active Directory      

Window 2000/2003 server computer. At least one NTFS partition. Static IP address. At least 1GB free hard disk space. LAN card enabled and connected to the network. Install DNS, if not installed of Active Directory and configure it.

It should be noted that active directory cannot work without DNS.DNS isautomaticall y installed and configured during the Active Directory installation.

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2.7.1.4 Installation of Active Directory First of all fill the static IP address, then install DNS service into it and after that install the Active Directory.               

start→ run→ dromo. Ok Welcome to active directory → next→ next. Select domain controller for a new domain e.g. (gmail.com) Next. Domain NETBIOS name (gmail.com) Next. Data folder, folder new tech directory service → next (SYS VOL) Next Click on install and configure the DNS server on this computer to use this DNS server as its preferred DNS server. Tick on permission compatible only with window server. Next Enter the restore mode and the . next→ next → finish. now restart computer.

Command used for the removal of Active Directory 

start→ run→ dromo.

This command is also used to remove active directory, if after this command the active directory is not removed then type.   

start→ run. cmd→dromo /forceremoval. Ok

How to identify Active Directory installation 

Start → tool.

After that if three options specified if come, it means that Active Directory has been installed.   

Active Directory domain and trusts Active Directory sites and services Active Directory s and computer

Open DNS console by  

tools → DNS. Forward lookup zone

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msdcs.exam.edu start of authority (SOA) name server (NS) Now ping active directory with domain name like 

start→ run→ ping gmail.com.

Backup of Active Director Active Directory backup come in use when there is some problem in active directory. If there is any problem in active directory then remove it and restore the backup.      

Start→ run→ntbackup→ok. Select advance mode and untick that is already ticked. Select backup. Select system state. Change backup path browse keep in your hardware and then send it to the pen drive. D:\adbackup

2.7.2 CHILD DOMAIN A domain is created say ―xyz.com‖. this domain is known as parent domain or the root domain. Now ―chd.xyz.com‖ will be the child domain or the sub domain of xyz.com.

Fig 10 : parent-child relationship model A child domain is created to ease istration in a very large domain network. We can create the parent domain in the head office of the company and the child domain in the branch offices. Each branch office will have its own to manage the s of the child domain present in the branch office. A true relationship is automatically created between the parent domain and the child domain. This means s in the child domain can access the file server of the parent domain. Moreover s of either domain can use clients of either domain for logging in the domain

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but a can always logon only in the domain in which his resides, though he physically can use client pc of parent or client domain. s of either domain can logon its own domain from either side but only when it use its own domain name. s of parent domain can communicate with child domain but he has to use its domain name for that.

2.7.2.1 Steps to create child domain

First of all install the active directory on pc1 i.e. on the parent domain. Now make Tom on it. On pc2 create the child domain, then make s on it, - Ram Below are the steps to create child domain.          

Fill the IP address in the child domain. Now ping to the parent domain with the domain name (xyz.com). Run →dromo→ ok. Next → select domain controller for a new domain. Next → select child domain and existing domain name (mcse.com) Next Enter name, and domain name. Enter parent domain name also enter child domain name. enter complete DNS name i.e. xyz.mcse.com. next→ next→ next→ next.

It should be noted that parent domain can logon into child domain but on the other hand child domain cannot logon to the parent domain. Also parent domain can apply policies or security on the child domain. Make the client member by entering particular with its domain name.     

First right click on My Computer Properties Computer name Change Write domain name →ok Now logoff start and then write name – Tom Domain name - mcse.com

Again logoff and check the other

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Start- name- abc Domain name – mail.mcse.com

2.8 INTERNET SHAREING We can share a single internet connection to multiple computers with the help of networking or internet sharing. There are four ways to share internet. (i) (ii) (iii) (iv)

Direct sharing ICS – Internet connection sharing Win Proxy NAT – Network Address Translation

2.8.1 Direct Sharing Internet sharing can be done between computers directly, just by taking internet connection directly from ISP (Internet Server provider), then it is provided to ADSL model, ADSL modem is connected to the ISP through RJ-11 connector. Then it is connected to the switch with RJ-45 connector. Switch, further connects computers those have to be provided with internet connection. The scenario for direct sharing is as shown in figure:

Fig: 11: Direct Sharing Scenario ADSL modem has IP address 192.168.1.1. All the PCs are assigned with a DNS (Domain Name Server) and GW (gateway) -192.168.1.1. Also DH (Dynamic Host Communication Protocol) is enabled which will provide IP addresses to the PCs automatically. 2.8.2 ICS (Internet Connection Sharing) Internet Connection sharing provides an alternate way to provide Internet Sharing.ICS requires a server with two network interfaces, one for the private internal network configured with IP 192.168.0.1 address and an adapter for public connection. ICS requires two connections in order to work: one public and one private i.e. ICS server requires

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two LAN cards, Internal (Private) and External (Public). Internal LAN card uses Local LAN card (L2) and External LAN card (L1) is used by Internet. ICS is designed to be as simple as possible. ICS works on following windows: XP, Vista, 2K3 Server, 2k3Server SP1.it doesn‘t work on the server in which AD+SP1 is present. The scenario for ICS is shown below:

Fig 12: ICS scenario Note :- When we configure ICS then the local card detect 192.168.0.1 addressautomatically How to configure ICS        

Open network and sharing center. Network- Properties Click on Manage network connections. Right click on LAN Card which is used for internet- properties Click on sharing Enable ICS Ok Yes

2.8.3 Win Proxy Server Win Proxy is a third party software which is used for sharing internet and we can also block the web site with the help of win proxy. WIN Proxy s all the three classes A, B , C also it is ed by all operating systems. The scenario for WIN proxy is shown below:

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Fig 13: scenario of win proxy server In win proxy as shown in the scenario above we can share internet. First of all a ADSL modem is connected to the ISP (Internet Service Provider) by a RJ-11 connector and other end of ADSL modem is connected to the PC1 through RJ-45. Assign IP address192.168.1.1 to the ADSL modem also enable the DH server and set the start IP address of 192.168.1.2 and end IP address of 192.168.1.254. Then after ADSL modem connect PC1, assign GW 192.168.1.1 2.8.4 NAT (Network Address Translation) If we have to connect many computers with a single IP address then we will use NAT. NAT exchange IP packet between local network and internet. The routing and remote access server of window 2K3 server provides us with a component known as NAT. By enabling NAT on a Server 2003 system, you allow connected s on a private system to share a single connection to access a public network such as the internet i.e. NAT enable multiple client computer to connect the internet through a single publicly ed IP address. A NAT server translates private IP address to public addresses. NAT eliminates the need for large number of IP addresses by mapping externally assigned IP addresses.

Fig 14: NAT server When deploying NAT, it is needed to configure setting on both the client side and the server side. On the server side of NAT fill the IP address statically.

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2.8.4.1 Steps to enable NAT server    

Open internet → Tools → Internet options Connections → LAN settings Untick the IP and port address Ok → ok → give site name

On the client side of NAT, client side is configured to obtain IP addressesautomaticall y and then restart the client system. Assuming NAT is used for address assignment, the client system will receive T/IP information from the NAT server. The client information includes:   

IP address from 192.168.0.0 private addressing range. Subnet masks (255.255.255.0). DNS server address, which would be the address of the NAT interface on the server.

With the client side configured, there are few things to do on NAT server: The first step to configure NAT server is to actually install the routing and remote access services. to do this start the routing and remote access service setup wizard.       

Start tools routing & remote access Right click on My computer → right click on computer name Select option configure and enable routing & remote access Welcome to routing → next → next Select NAT → next Select LAN card which is to be connected to internet Next→ next

From any of the four methods of internet sharing only method is used at a time to rmove the other method  Go to start → setting  Add & remove  Change / remove .tick on remove

2.9 VIRTUAL PRIVATE NETWORK (VPN) A virtual private network is used to convert public network address to private network. All the clients of VPN dial to public IP address of VPN server and receive private IP from virtual VPN dynamic host protocol (DH).in VPN one can have multiple virtual connections to a single IP address. This way ,one network card can host several inbound connections, rather than require a modem and telephone line for each simultaneous remote .

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Fig 15 : scenario of VPN server Using VPN server we can connect many private networks to internet services i.e the remote connection. We can create a private network through public network, we can use firewall for security and data encryption in VPN server. 3.9.1 VPN components (i) (ii) (iii) (iv)

VPN server VPN Clients WAN Option Security Options

VPN Server VPN clients establish connection to VPN server. They can also be routers that obtain the router-to-router secure connection. VPN client software is included in all the modern window operating systems, including Window 2003 server. Router-to router VPN connection can be made from computers running server2003 and Windows 2000 running Routing and Remote Access. Additionally, any client that s PPTP or L2TP connections can be VPN clients of a window server 2003 system. WAN Options These provide the physical mechanism for ing data back and forth. These connections typically include such similar network technologies such as T1or frame relay. In order for VPN connections to be successful, the VPN client and VPN server must be connected to each other using either permanent WAN connection or by dialing into an internet server provider (ISP). Security Options Since a VPN uses a network that is generally open to the public, it is important that the data ed over the connection remain secure. To aid with securecommunication

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routing and remote access s such security measure as logon and domain security, data encryption, smart cards, IP packet filtering and caller ID. 2.9.2 Types of VPN (i ) PPTP (Point to Point Tunneling Protocol ) (ii) L2TP (Layer 2 Tunneling Protocol) according to CCNA Point to Point Tunneling Protocol (PPTP) PPTP is Microsoft‘s legacy protocol for ing VPN. It was developed in conjunction with other communications companies such as Robotics as an extension to the PPP protocol. PPTP encapsulates IP or IPX packets inside of PPP datagram‘s. This means that you can remotely run programs that are dependent upon particular network protocols. One of the keys to about PPTP is that the protocol providesencryption capabilities, making it much safer to send information over non secure networks. Layer Two Tunneling Protocol (L2TP) L2TP is a standard based encapsulation protocol with roughly the samefunctionality as a Point-to-Point Tunneling Protocol (PPTP). One of the key differences between Window‘s server 2003 implementation of L2TPand it cousin PPTP is thatL2TPis designed to run natively over IP networks only. This implementation of L2TPdoes not s native tunneling over X.25, frame relay, or ATM networks. Like PPTP, L2TPencapsulates Point-to-Point Protocol (PPP) frames, which then encapsulate IP or IPX protocols, allowing s to remotely run programs that are dependent on specific network protocols. But unlike the PPTP protocol, L2TP does not provide encryption of the data. For data security L2TPrelies on the services of other standards- based protocol, IPSec. 2.9.3 How to configure VPN           

Start → istrative tools Routing and remote access Right click on computer name configure and enable routing and remote access Next → select remote access (dial up or VPN) Next →VPN → next Select LAN card which is connected to internet (175.15.15.50) public IP Disable enable security → next From a specific range of address → next → new Enter the required range Ok→ next→ no radius Next → finish

2.9.4 Create s in VPN server  

Open properties→ dial in→ allow access Apply→ ok

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2.9.5 Working on Clint Side      

Right click on my network places → properties Double click on new network wizard → next connect to network at my work place → next virtual private network connection → next enter company name (abc) → next finish

2.10 ROUTING It is a process of transferring information through an inter network i.e. from one network to another. Routing connect different networks having ID help in process of routing. The dial-in properties also allow for specific IP address to be assigned to a . This is the only way in Window Server 2003 that you can assign a specific IP to a . To assign a specific IP to a , check the box next to assign A Static IP Address and enter a valid IP in the space provided. Static routing can also be specified as per . By defining static routes, s can be limited to only specific parts of networks. In an internetwork a router must then about all the networks present in the for effort websites, there are hardware routers like CISCO. Even win 2003 server computer configured as router. In simple words Router is a computer with two network cards. These two network cards, then, are attached to two different logical IP networks. The routing table helps direct traffic that is ed through the router. Now when there is a router, also there is a routing table, there is a need to configure the router in order for that router to along traffic to the proper network. There are two ways the routing table can be built and modified: either manually or automatically. 2.10.1 Types of Routing (i) Static Routing (ii) Dynamic Routing 2.10.1.1 Static Routing In this routing information required for routing is manually entered into the router by . How to configure LAN routing       

enter the static IP in the router tools Routing and remote access Right click on computer name (pccl) Configure and enable routing and remote access Next → custom configuration Select LAN routing → next → finish

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

Yes and logon to see IP table route

Enable LAN routing Interface WAN

enable LAN routing Interface WAN 10.0.0.0

IP 172.15.0.0

IP 10.0.0.0

SNM 255.255.0.0

SNM 255.0.0.0

GW 20.0.0.2

GW 20.0.0.1 Fig 16 : scenario for LAN routing

How to configure static routing At Router R1:      

Enable LAN routing Right click on static route Interface WAN Destination 172.15.0.0 Mask 255.255.0.0 GW 20.0.0.2

At Router R2:      

Enable LAN routing Right click on static route Interface WAN Destination 10.0.0.0 Mask 255.0.0.0 GW 20.0.0.1

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Fig 17 : static routing 2.10.1.2 Dynamic Routing The other way to manage a router routing tables is to let the computer do it for you. Just like DH allocate IP addresses, configuring the dynamic routing protocol usually means less errors due to human error, and less istrative overhead. In dynamic routing, routing information is automatically entered in the router using protocols like RIP AND OSPF. These routing protocols used by Window Server 2003 use one of two kinds of algorithms to determine the best possible path for a packet to get to its destination, either distance vector or link state. RIP is used for small networks whereas OSPF is used for large networks. Routing Information Protocol (RIP) The distance vector protocol in use on Window 2003 is called RoutingInformation Protocol (RIP) for IP. This protocol was designed for the exchange of the routing information within a small to medium size IP network. When Router is enabled on Window 2003 machine, the routing table includes entries only for the networks that are physically connected. When RIP is enabled for an interface, the router will periodically send an announcement of its routing table to inform other RIP routers of the networks it can reach. RIP version1 uses broadcast packets for its announcement. RIP version2 offers an improvement andcan be configured to use either multicast or broadcast packets when communicating with other routers. Also, RIP version2 offers more flexibility in sub netted and classless inter domain routing (CIDR) environments. The biggest advantage of RIP is its simplicity. With a few clicks in the Routing and Remote Access Server and MMC console, you can deploy RIP. With the RIP dynamic routing protocol installed on Window‘s Server 2003, you get the following features: (i)

RIP version1 and version2, with the ability to configure individual network cards with separate versions.

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(ii) (iii)

(iv) (v)

Calculations used to avoid routing loops and speed recovery of the network whenever topology changes occur. Route filters; you can configure RIP to except information from only certain networks, and also choose which routes will be shared with RIP routers. Peer filters, which allow control over which router announcements are accepted. Simple authentication .

But there are significant drawbacks, which makes RIP a poor, if not unusable solution for large networks. For example, the maximum hop count used for RIP routersis15, making network 16 hops away (or more) unreachable where RIP is concerned. Open Shortest Path First (OSPF) Where RIP is built to work to work in smaller networks, the Open Shortest Path First (OSPF) routing protocol is designed for large or very large networks. The goal is the same: information about connection to other networks is shared from one router to another. It offers several advantages over RIP, especially significant in large networks: (i) (ii) (iii)

Routes calculated with OSPF are always loop free. OSPF can scale much more easily than RIP. Reconfiguration for network topology changes is faster.

The biggest reason OSPF is the choice in large networks is its efficiency; instead of changing routing table via broadcast the way RIP does, OSPF configured routers maintain a map of the network. The mapping is called the link state database; OSPF routers keep the link state database up to date. Once changes have been made to link state database, an OSPF router‘s link state database is recalculated. As the networks start to multiply, the size of the link state database increases, and a corresponding hit on router performance results. To combat this, OSPF sub divide the network into smaller sections, called areas. Areas are connected to each other through a backbone area, with each router only responsible for the link state database for those areas connected to the routers. Area Border Routers (ABRs) then connect one backbone area to another. The biggest drawback of OSPF is its complexity; OSPF requires proper planning and is more difficult to configure and ister.

2.11 EXCHANGE SERVER Exchange server is a mail server; we can send and receive mail from one to another . Exchange server is the mail server of Microsoft.

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2.11.1 Elements of Exchange Server Mail Server A server which helps to the s to send and receive mail is called mail server Mail Box A storage place where senders and receivers mails are stored 2.11.2 Exchange Version Table 10: Exchange Server with different operating systems Exchange Version

Exchange server 5.5 Exchange server 2000

Operating System

WIN NT or 2000 server (without SP) WIN NT or 2000 server (SP3,SP4) without (SP) WIN 2000 server or WIN 2003 server (SP4)

Exchange server 2003 Exchange server 2007

without SP WIN 2003 server or R2/WIN 2008 server with SP1

Where SP stands for Service Pack. Service Pack are the services which are loaded externally to remove some bugs that come during installation of server CD. 2.11.3 Requirements for Exchange Server Protocols Required POP3 (Post Office Protocol) This protocol is used for receiving e- mails. IMAE4 (Internet Messaging Access Protocol) This protocol is advance version of POP, this is also used to receive mail. LMTP (Local Mail Transfer Protocol)/SMTP (Simple Mail Transfer Protocol) This protocol is used to send mails. NNTP (Network News Transfer protocol) This protocol is used for transferring messages on internet.

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Hardware Requirements Processor: min. 133MHz Rec. 733MHz RAM: min. 256MB Rec. 512MB Other Requirements OS: 2k or 2k3 Servers NTFS partition Static IP address Active Directory DNS installation with AD zone IIS installed with ASP.net, SMTP, NNTP and www service

2.12 Open System Interconnection (OSI) Model OSI model is the layer approach to design, develop and implement network. OSI provides following advantages: (i) (ii) (iii)

Development of new technology will be faster. Devices from multiple vendors can communicate with each other. Implementation and troubleshooting of network will be easy.

2.12.1 Description of Different Layers Application Layer Application layer accepts data and forward into the protocol stack. It creates interface between application software and protocol stack. Presentation Layer This layer decides presentation format of the data. It also able to performs other function like compression/decompression and encryption/decryption. Session Layer This layer initiate, maintain and terminate sessions between different applications. Due to this layer multiple application software can be executed at the same time. Transport Layer Transport layer is responsible for connection oriented and connection lesscommunicat ion. Transport layer also performs other functions like (i) (ii)

Error checking Flow Control Buffering Windowing Multiplexing

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(iii) (iv) (v)

Sequencing Positive Acknowledgement Response

Network Layer This layer performs function like logical addressing and pathdetermination. Each net working device has a physical address that is MACaddress. But logical addressing is easier to communicate on large size network. Logical addressing defines network address and host address. This type of addressing is used to simplify implementation of large network. Some examples of logical addressing are: - IP addresses, IPX addresses etc. Network layer has different routing protocols like RIP, EIGRP, BGP, and ARP etc. to perform the path determination for different routing protocol. Network layer also perform other responsibilities like defining quality of service, fragmentation and protocol identification. Data Link Layer The functions of Data Link layer are divided into two sub layers

(i)

(ii)

 Logical Link Control  Media Access Control Logical Link Control defines the encapsulation that will be used by the NIC to delivered data to destination. Some examples of Logical Link Control are ARPA (Ethernet), 802.11 Wi-Fi. Media Access Control defines methods to access the shared media and establish the identity with the help of MAC address. Some examples of Media Access Control are CSMA/CD, Token ing.

Physical Layer Physical Layer is responsible to communicate bits over the media this layer deals with the standard defined for media and signals. This layer may also perform modulation and demodulation as required.

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2.13 ROUTERS 2.13.1 Router Architecture and its Key Component LAN Processor I/O Controller WAN Memory controller

RAM

Ports

BIOS ROM Flash RAM O/S

IOS

NVRAM

startup configuration Fig 18 : Architecture of router Processor Speed: - 20 MHz to 1GHz Architecture: - RISC Reduce Instruction set computer Manufacturers: - Motorola, IBM, Power PC, Texas, Orion, Intel Flash RAM Flash memory is just like a hard copy of the computer. Flash RAM is the permanent read/write memory. This memory is used to store one or more copies of router O/S. Router O/S is also called IOS (Internetwork Operating System).The size of Flash RAM in the router is 4MB to 256MB. This memory is Electrically Erasable Programmable Read Only Memory (EEPROM).

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NVRAM NVRAM is a ―Non Volatile Random Access Memory‖. It is used to store the startup configuration of the Router. It is on chip RAM, its size is 32kb. RAM (Random Access Memory) It is a volatile memory. All the activities we do are stored in RAM , this means that it holds the running configuration. RAM of the router is divided into two logical parts. • •

Primary RAM Shared RAM

Primary RAM Primary RAM is used for: (i) (ii) (iii) (iv) (v)

Running copy of IOS. Running configuration Routing table Address Resolution Protocol (ARP) table (IP address to MAC address) Processor & other data structure

Shared RAM Shared RAM is used as a buffer memory to share the data received from different interfaces. Size of RAM in a router may vary from 2 MB to 512 MB .The types of memory that may be present in a RAM are: (i) (ii) (iii)

DRAM -> Dynamic RAM EDORAM -> Extended Data Out RAM SDRAM -> Synchronous Dynamic RAM

ROM (Random Access Memory) It has four components: POST (Power on Self-Test) It performs hardware testing. BOOT Strap Boot strap specifies from where and which inter operating system is to be loaded. 2.13.2 Router Interfaces & Ports Interface is used to connect LAN networks or wan networks to the router. Interface will use protocol stacks to send/receive data. Ports are used for theconfiguration of routers. Ports are not used to connect different networks. The primary purpose of port is the management of router.

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2.13.2.1 Router Interface

Table 11: Router interfaces and connectors

AUI – Attachment Unit Interface EPABX – Electronic Private Automatic Branch PSTN – Public Services Telephone Network 2.13.2.2 Router Ports Table 12: Router Ports

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2.13.3 Modes of Router When we access router command prompt the router will display different modes. According to the modes, privileges and rights are assigned to the . mode Router> In this mode, we can display basic parameter and status of the router we can test connectivity and perform telnet to other devices. In this mode we are not able to change and save router configuration. Privileged mode Router# In this mode, we can display all information, configuration, perform istration task, debugging, testing and connectivity with other devices. We are not able to perform here configuration editing of the router. The command to enter in this mode is ‗enable‘. We have to enter enable or enable secret to enter in this mode. Enable secret has more priority than enable . If both s are configured then only enable secret will work. Global configuration Route(config)# This mode is used for the configuration of global parameters in the router. Global parameters applied to the entire router. All the changes are performed in this mode. But here we cannot see and save the changes. For e.g.: - router hostname or access list of router, , Banner, Routing, Security. The command to enter in this mode is ‗configure terminal‘ Line configuration mode In this mode we can set the of the mode, i.e. to set mode .This mode is used to configure lines like console, vty and auxiliary. There are main types of line that are configured. (i)

Console Router(config)# line console 0

(ii)

Auxiliary Router(config)# line aux 0

(iii)

Telnet or vty Router(config)# line vty 0 4

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Interface configuration mode In this mode we can set ip addresses of the interfaces. This mode is used to configure router interfaces. For e.g:- Ethernet, Serial, BRI etc. Router(config)#interface Router(config)#interface serial 1 Routing configuration mode This mode is used to configure routing protocol like RIP, EIGRP, OSPF etc. Router(config)#router <protocol> [ ] Router(config)#router rip Router(config)#router eigrp 10 2.13.4 Configuring There are five types of available in a router

Console router#configure terminal router(config)#line console 0 router(config-line)# <word> router(config-line)# router(config-line)#exit

To erase do all steps with no command. Vty router>enable router#configure terminal router(config)#line vty 0 4 router(config-line)# <word> router(config-line)# router(config-line)#exit

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Auxiliary router#configure terminal router(config)#line Aux 0 router(config-line)# <word> router(config-line)# router(config-line)#exit Enable router>enable router#configure terminal router(config)#enable <word> router(config)#exit Enable Secret Enable is the clear text . It is stored as clear text inconfiguration where as enable secret is the encrypted . Router>enable Router#configure terminal Router(config)#enable secret <word> Router(config)#exit Encryption all s All s other than enable secret are clear text . The command to encrypt all are. Router#configure terminal Router(config)#service -encryption 3.13.5 Managing Configuration There are two types of configuration present in a router (i) (ii)

Startup Configuration Running Configuration

Startup configuration is stored in the NVRAM. Startup configuration is used to save settings in a router. Startup configuration is loaded at the time of booting in to the Primary RAM.

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Running Configuration is present in the Primary RAM wherever we run a command for configuration, this command is written in the running configuration. To save configuration Router#copy running-configuration startup-configuration Or Router#write To abort configuration Router#copy startup-configuration running-configuration To display running-configuration Router#show running-configuration To display startup configuration Router#show startup-configuration

Configuring Host Name Router#configure terminal Router(config)#hostname #exit or end or /\z Router#config terminal Router(config)#hostname r1R1(config)# Configuration Interfaces Interfaces configuration is one of the most important part of the router configuration. By default, all interfaces of Cisco router are in disabled mode. We have to use different commands as our requirement to enable and configure the interface. Router#configure terminal Router(config)#interface <no> Router(config-if)#ip address <mask> Router(config-if)#no shutdown Router(config-if)#exit

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To display interface status Router#show interfaces (to show all interfaces) Router#show interface <no> This command will display following parameters about an interface (2) Status (3) Mac address (4) IP address (5) Subnet mask (6) Hardware type / manufacturer (7) Bandwidth (8) Reliability (9) Delay (10) Load ( Tx load Rx load) (11) Encapsulation (12) ARP type (if applicable) (13) Keep alive Configuring optional parameter on WAN interface Router#configure terminal Router(config)#interfac <no> Router(config-if)#encapsulation <protocol> Router(config-if)#clock rate Router(config-if)#end Command displaying history of Router To display commands present in history Router#show history To display history size Router#show terminal To change history size Router#config terminal Router(config)#line console 0 Router(config-if)#history size Router(config-if)#exit Configuring Banners Banners are just a message that can appear at different prompts according to the type. Different banners are: • Message of the day (motd)This banner appear at every access method • Appear before prompt

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• Exec Appear after we enter to the execution mode • Incoming Appear for incoming connections Syntax:Router#config terminalRouter(config)#banner <delimation char>Text Massage<deli mation char> Router(config)# Example Router#config terminal Router(config)#banner motd $ This router is distribution 3600 router connect ed to Reliance $ Router(config)# To set time in router We can configure router clock with the help of two methods: (i) Configure clock locally (ii) Configure clock on NTP server (Network Time Protocol)Router does not have battery to save the clock setting. So that clock will reset to the default on reboot. To display clock Router#show clock To configure clock Router#clock set hh:mm:ss day month year Router#clock set 7:15:10 9 June 2009 To configure clock from NTP server Router#config terminal Router(config)#ntp server Router(config)#exit C:\>ping pool.ntp.org To get ntp server ip from internet C:\>route print

2.14 SUBNETTING Subnetting is a process or a technique to divide large and complex networks in to smaller parts or smaller networks and each network is called as subnet. Subnetting is done to reduce the wastage of IP addresses ie instead of having a single huge network for organization smaller networks are created within a given huge network. Subnetting allows the to create multiple logical networks within a single Class A, B or C based networks. In subnetting, the IPv4 address is broken into two parts; network id and host id. This process borrows bits from the host id field. In this process, the network size

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does not shrink but the size of hosts per network shrinks in order to include sub-networks within the network. 2.14.1 Advantages of subnetting • Size of the physical networks is reduced and hence easy to manage. • Reduce network traffic. • Easy to troubleshoot. • Reduce the wastage of IP address. Subnet Mask A subnet mask specifies the part of IP address that is to be used for identifying a sub network. A subnet mask when logically ANDed with IP address provides a 32- bit network address. This binary address gives the first address in the subnet block specified in the large network. Default Mask Classfull addresses consists of three classes; Class A, Class B, Class C used for subnet.Each class has a default subnet mask C lass A consists of eight 1s in the network address field and 24 0s in remaining field, Class B consists of 16 1s in network address field and 16 0s in remaining field, and Class C contains 24 1s in the network address field and remaining 8 bytes as 0s. the default address mask in binary and dotted-decimals shown in the table Table 13 Default address mask in binary & dotted decimals

To Calculate the Subnet Mask

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1. Identify the class of address assigned. For this example the class of IP address is Class B. 2. check the default address mask for the appropriate class and convert it to binary format .for this example the default address mask is 255.255.0.0 and the equivalent binary format is; 11111111.11111111.00000000.00000000 3. check the no. of 1s in the default mask. E.g. this address contains 16 1s in classB, 16 bits 2 octat are for net id and the last 16 bits 2 octates are for host id. 4. now if we need 9 subnets. This no. 9 is not a power of 2. the next no. that is power of 2 and greater than 2 is 16. So, we require 4 extra 4 extra 1s in the network field which has to be borrowed from the host id field. 5. the total no. of 1s is 16+4=20, as 16 1s are from network id and 4 1s are of additional bits required for sub network. The no. of 0s in the n/w is 3220=12.which defines whole address. 6. hence address is given as 11111111.11111111.11110000.00000000 and in decimal format can be given as 255.255.240.0 Table 14: decimal and binary values of subnet mask

Decimal

0 128 192 224 240 248 252 254 255

Binary

00000000 10000000 11000000 11100000 11110000 11111000 11111100 11111110 11111111

2.14.2 Types of Subnetting • Fixed Length Subnet Mask (FLSM) • Variable Length Subnet Mask (VLSM) Steps of Subnetting for FLSM For IP address 192.168.10.0 (Class C) Step 1: • Identify the total no. of subnets 2^n = no. of subnets • Where n are the no.s and borrowed bytes from host ID portion. Let we are given that we have to make 4 subnets. Therefore 2^n =4 i.e. n=2 Step 2: • To identify the total no. of the valid hosts for each subnet.

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• 2^m-2= no.of valid hosts. Where m are the remaining no. of bits in host ID 2^62=62 Step 3: • Calculate the subnet mask and range • Subnet mask for n/w 192.168.10.0/26 is11111111.11111111.11111111.1100000000 i.e. 255.255.255.192 • range=> 256-192=64 Step 4: •Identify the total no of subnets, no. of valid hosts and the broadcast address. Table 15: showing subnet mask, valid hosts, broadcast address Subnetwork

Valid Host

Broadcast Address

192.168.10.0

192.168.10.1 to 192.168.10.63

192.168.10.63

192.168.10.65 to 192.168.10.126

192.168.10.127

192.168.10.128

192.168.10.129 to 192.168.10.190

192.168.10.191

192.168.10.192

192.168.10.193 to 192.168.10.254

192.168.10.255

192.168.10.64

VLSM In VLSM to allocate IP addresses to subnets depending upon the no. of hosts. The network having more no of hosts is given priority and the one having least no of host comes at last and for each network the subnet is assigned separately. As in the scenario given:

Fig 19: variable subnet mask

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3.15 TELNET Telnet stands for terminal network, telephone network, terminal encapsulation on the network. Purpose of Telnet is to access the remote device in order to configure it. It provides textual access of the remote device. It uses the services of T. Telnet service is used where small bandwidth is low. It provides textual access of the remote device. Port number of Telnet is 23. 3.15.1 To Access the Device Remotely For this purpose we have to assign the IP addresses to the PCs and the interfaces. For Telnet the Routers are to be configured with RIP version1 , so that the device can ping each other. Also DCE cable is used to connect the Routers. The serial link should have the speed of 64K also apply vty and enable secret . Set up the Routers so that they can manage via Telnet. First of all select the PCs and the routers connect the ports to the router, double click on router, switch off the router if it is on. Then select the serial port according to the routers, switch on the router. Select the cable to connect the Routers. Router to Router connections are made by the serial cable, so go on first Router select the serial port ass0/1/0 in the scenario, then go to the other Router and connect the serial cable at interfaces1/0. Accordingly connect the third Router with interfaces s1/1 and s1/2. Now connect the PCs to the routers, to do this first select the console cable, click on the PC select RS232 option, then connect it on the Router and select console cable. Now select cross- over cable on the PC select Fast Ethernet option and on the Router selectf0/0 option now as the PCs and Routers are connected to each other assign IP addresses to the PCs and the Routers. According to the fig set the IP addresses of the PCs→ double click on the PC→ choose the option of desktop→ IP configuration. Now set the IP address, subnet mask, and the default gateway. Likewise set the IP address of all the PCs. Now set the IP address of the interfaces of router. 3.15.2 Commands to assign IP addresses to the interfaces: At Router1: Router> Router>enable Router#configure terminal Router(config)#interface f0/0 Router(config-if)#ip address 10.0.0.1 255.0.0.0 Router(config-if)#no shutdown

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Fig 20: scenario of Telnet Router# Router#configure terminal Router(config)#interface s0/1/0 Router(config-if)#ip address 40.0.0.1 255.0.0.0 Router(config-if)#no shutdown Router(config)#interface s0/1/0 Router(config-if)#clock rate 64000 Router(config-if)#no shutdown Now to check the assigned IP addresses to the interfaces the command used is Router#show ip interface brief At router 2: Router#configure terminal Router(config)#interface f0/0 Router(config-if)#ip address 20.0.0.1 255.0.0.0 Router(config-if)#no shutdown Router# Router#configure terminal Router(config)#interface s1/0 Router(config-if)#ip address 40.0.0.2 255.0.0.0 Router(config-if)#no shutdown Router#configure terminal Router(config)#interface s1/1 Router(config-if)#ip address 50.0.0.1 255.0.0.0 Router(config-if)#no shutdown Router(config)#interface s1/1 Router(config-if)#clock rate 64000 Router(config-if)#no shutdown

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At router 3: Router#configure terminal Router(config)#interface f0/0 Router(config-if)#ip address 30.0.0.1 255.0.0.0 Router(config-if)#no shutdown Router#Router#configure terminal Router(config)#interface s1/0 Router(config-if)#ip address 50.0.0.2 255.0.0.0 Router(config-if)#no shutdown To Telnet a device from Router At all the Routers use these commands Router(config)#line vty 0 4 Router(config-line)# cobra Router(config-line)# Router(config)#enable cobra Router(config)#enable secret cobra1 To telnet a device from router Router#telnet Or Router>telnet To exit from telnet session Router#exit To exit from a hanged telnet session Ctrl+shft+6 Or Router#disconnect To display connected session Router#show sessions This command shows those sessions, which are created or connected by us. If we want anyone can telnet our router without then on the line vty type command ―No ‖.

2.16 ROUTING Routing is a process or technique to identify the path from one network to another. Routers don‘t really care about hosts—they only care about networks and the best path to each network. To route the packet the router must know the following things: • Destination network • Neighbour device from witch it can learn about remote Networking. • Possible number of routers to reach the destination. • Best route to reach the destination. • How to maintain & the routing information.

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3.16.1 TYPES OF ROUTING • Static routing. • Default routing. • Dynamic routing. 3.16.1.1 STATIC ROUTING In static routing an specifies all the routes to reach the destination. Static routing occurs when you manually add routes in each router‘s routing table. By default, Static routes have an istrative Distance (AD) of 1 Features :  There is no overhead on the router U.  There is no bandwidth usage between routers.  It adds security, because the can choose to allow routing access to certain networks only.

Advantages of static routing (1) Fast and efficient. (2) More control over selected path. (3) Less overhead for router. (4) Bandwidth of interfaces is not consumed in routing updates.

Disadvantages of static routing (1) More overheads on . (2) Load balancing is not easily possible. (3) In case of topology change routing table has to be change manually.

Syntax for Static Routing Router (config)#ip route <destination N/w> <Subnet mask> [ Permanent]. To check the routing table of router Router # show ip route

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Fig 21: scenario of static routing Static routing of router (R1) Router(config)#ip route 20.0.0.0 255.0.0.0 40.0.0.2 Router(config)#ip route 30.0.0.0 255.0.0.0 40.0.0.2 Router(config)#ip route 50.0.0.0 255.0.0.0 40.0.0.2 Router(config)#interface so/1/0 Router(config)# clock rate 64000 Router # show ip route Static routing of router (R2) Router(config)#ip route 10.0.0.0 255.0.0.0 40.0.0.1 Router(config)#ip route 30.0.0.0 255.0.0.0 50.0.0.2 Router#show ip route Router(config)#interface s1/0 Router(config)# clock rate 64000 Router(config)#interface s1/1 Router(config)#clock rate 64000 Router#show ip route Static routing of router (R3) Router(config)#ip route 10.0.0.0 255.0.0.0 50.0.0.1 Router(config)#ip route 20.0.0.0 255.0.0.0 50.0.0.1 Router(config)#ip route 40.0.0.0 255.0.0.0 50.0.0.1 Router(config)#interface s1/0 Router(config)# clock rate 64000 Router#show ip route 2.16.1.2 DEFAULT ROUTING Default routing is used to send packets with a remote destination network not in the routing table to the next-hop route. Default routing is also a type of static routing which reduces the routing overhead & default routing is also used with stub networks. Stub networks are those having a single exit interface. Default routing is also used

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for unknown destination. A special address is used to perform the default routing ie.0.0.0.0 The scenario for default routing is same and but the commands used at the router shaving single exit interface like R1 and R3 have different commands. At Router (R1) Router(config)#ip route 0.0.0.0 0.0.0.0 40.0.0.2 Router#show ip route At Router (R3) Router(config)#ip route 0.0.0.0 0.0.0.0 50.0.0.1 Router#show ip route 2.16.1.3 DYNAMIC ROUTING Dynamic routing is when protocols are used to find networks and update routing table on routers. A routing protocol defines the set of rules used by router when it communicates routing information between neighbor routers. In dynamic routing, we will enable a routing protocol on router. This protocol will send its routing information to the neighbor router. The neighbors will analyze the information and write new routes to the routing table. The routers will routing information receive from one router to other router also. If there are more than one path available then routes are compared and best path is selected. Some examples of dynamic protocol are: -RIP, IGRP, EIGRP, OSPF There are two type of routing protocols used in internetworks: • Interior Gateway Protocols (IGPs) IGPs are used to exchange routing information with routers in the sameA utonomous System(AS) number. Routing which is performed within a singleautonom ous system is known as interior routing. The protocol that are used to perform this type of routing are known as IGP(Interior Gateway Protocol). These protocols are:(i) RIPv1 (Routing Information Protocol Version 1) (ii) RIPv2 (Routing Information Protocol Version 2) (iii) EIGRP (Enhanced Interior Gateway Routing Protocol) (iv) OSPF (Open Shortest Path First) (v) IS-IS (Intermediate System to Intermediate System) • Exterior Gateway Protocols (EGPs) EGPs are used to communicate between different Autonomous System. Protocol that used to do this type of routing are called exterior gateway protocols. Autonomous System:An autonomous system is a collection of networks under a common istrative domain, which basically means that all routers sharing the same routing table information are in the same AS.

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3.16.2 Routing Protocol Basics (i) istrative Distances (ii) Routing protocol (iii) Routing Loops istrative Distances The istrative Distance (AD) is used to rate the trustworthiness of routing information received on a router from a neighbor router. An istrative Distance is an integer from 0 to 255, where 0 is the most trusted and 255 means no traffic will be ed via this route. If a router receives two updates listing he sane remote network, the first thing the router checks is the AD. If one of the d routes has lower AD than the other, then the route with the lowest AD will be placed in the routing table. If both d routes to the same network have the same AD, then routing protocol metrics (such as hop count or bandwidth of the lines) will be used to find the best path to the remote network. The d route with the lowest metric will be placed in the routing table. But if both d routes have the same AD as well as the same metrics, then the routing protocol will load-balance in the remote network. Router Source Connected interface Static Route EIGRP IGRP OSPF RIP External EIGRP Unknown 255

Default AD 0 1 90 100 110 120 170 This route will never be used

2.16.2.1 Classes of Routing Protocols There are three classes of Routing Protocol (i) Distance vector protocol (ii) Link state protocol (iii) Hybrid protocol. • Distance vector protocol The Distance-vector protocols find the best path to remote network by judging distance. Each time a packet goes through a router, that‘s called a hop. The route with the least number of hops to the network is determined to be the best route. The vector indicates the direction to the remote network. They send the entire routing table to directly connected neighbors. Ex: RIP, IGRP.  The distance-vector routing algorithm es complete routing table contents to neighboring routers.  A router receiving an update from a neighbor router believes the information about remote networks without actually finding out for itself.

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 It‘s possible to have network that has multiple links to the same remote network, and if that‘s the case, the istrative distance is checked first. If the AD is the

same, the protocol will have to use other metrics to determine the best path to use to that remote network.

Fig 22 : Routing table Converged Network

Fig 23 : Routing table of covered networks • Routing Loops Distance-vector routing protocols keep track of any changes to the internet work by broadcasting periodic routing updates out all active interfaces. This broadcast includes the complete routing table. Routing loops can occur because a every router isn‘t updated simultaneously. Routing Loops Example

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Fig 24: Routing loops The interface to Network 5 fails. All routers know about Network 5 from Router E. Router A, in its tables, has a path to Network 5 through Router B. When Network 5 fails, Router E tells Router C. This causes Router C to stop routing to Network 5 through Router E. But Routers A, B, and D don‘t know about Network 5 yet, so they keep sending out update information. Router C will eventually send out its update and cause B to stop routing to Network 5, but Routers A and D are still not updated. To them, it appears that Network 5 is still available through Router B with a metric of 3. The problem occurs when Router A sends out its regular 30-second―Hello, I‘m still here—these are the links I know about‖ message, which includes the ability to reach Network 5 and now Routers B and D receive the wonderful news that Network 5 can be reached from Router A, so Routers B and D then send out the information that Network 5 is available. Any packet destined for Network 5 will go to Router A, to Router B, and then back to Router A. This is a routing loop. • Link state protocol Also called shortest-pathfirst protocols, the routers each create threeseparate tables. One keeps track of directly attached neighbors, one determines the topology of the entire internet work, and one is used as the routing tables. Link state routers know more about the internet work than any distance-vector routing protocol .Link state protocols send updates containing the state of their own links to all other routers on the network Ex: OSPF • Hybrid protocol Hybrid protocol use aspects of both distance-vector and link state protocol. Ex: EIGRP

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2.18 Wi-Fi (WIRELESS FIDELITY) The term "Wi-Fi" suggests "Wireless Fidelity", compared with the longestablished audio recording term "High Fidelity" or "Hi-Fi". The term "Wi-Fi", first used commercially in August 1999. Wi-Fi is an IEEE standard 802.11. 2.18.1Wireless LAN Wi-Fi is also known as wireless LAN. The name of a popular wireless networking technology that uses radio waves to provide wireless high-speed Internet and network connections. "Wi-Fi works with no physical wired connection between sender and receiver by using radio frequency (RF) technology, a frequency within theelectromagnetic spectrum associated with radio wave propagation. When an RF current is supplied to an antenna, an electromagnetic field is created that then is able to propagate through space. The Typical Range of a Wi-Fi LAN The range of a home Wi-Fi LAN depends on the wireless access point (WAP)or wireless router being used. Factors that determine a particular WAP or wireless router‘s range are: • the specific 802.11 protocol employed • the overall strength of the device transmitter • the nature of obstructions and interference in the surrounding area A general rule of thumb in home networking says that802.11band802.11g WAPs and routers a range of up to 150 feet (46 m) indoors and 300 feet (92 m) outdoors. Another rule of thumb holds that the effective range of 802.11a isapproximately one-third that of 802.11b/g. Obstructions in home such as brick walls and metal frames or siding greatly can reduce the range of a Wi-Fi LAN by 25% or more. Because 802.11a employs a higher signalling frequency than 802.11b/g, 802.11a is most susceptible to obstructions.Interf erence from microwave ovens and other equipment also affects range. 802.11b and802.11g are both susceptible to these. 2.18.2 Wireless Standards The different wireless standards that are used for IEEE 802.11 standard are

Fig 29: IEEE 802.11 Standards

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802.11 It was released in year 1997. The standard was original of 802.11. the max. data rate of this is 2Mbps and frequency of this is 2.4GHz and can cover up to 46m. 802.11a It was modified in year 1999. this is improved version of original standard. Operates at the frequency of 5GHz, which is less crowded than 2.4GHz where telephones and microwaves may cause interference. Although the speed is up to 54Mbps, the range is only up to 75 feet or distance covered is 46m. 802.11a standard is incompatible with both 802.11b and g because it operates at a different frequency. 802.11b This standard was released in 1999. Operates on the 2.4GHz frequency band and can transmit data at speeds of up to 11Mbps within a range of up to 100-150 feet or a distance of 90m.Wireless range can be affected by reflective or signal-blocking obstacles, such as mirrors, walls, devices and location, whether indoors or outdoors. 802.11g This standard was released in 2003. The max. data rate for the standard is 54Mbps.It s a frequency range of 2.4GHz, covers a distance of 90m. 802.11n The latest version of IEEE 802.11 standard that is still in progress of develo pment. The next generation of high-speed wireless networking, capable of delivering the range and capacity to today's most bandwidth-hungry applications like streaming high definition video, voice, and music. Wireless-n is based on MIMO(Multiple Input, Multiple Output) technology, which uses multiple radios to transmit multiple streams of data over multiple channels. Operates in two modes of frequency 2.4GHz and 5.6GHz frequency band and can transmit data at speeds of up to 11Mbps within a range of up to 100-150 feet .Wireless range can be affected by reflective or signal-blocking obstacles, such as mirrors, walls, devices and location, whether indoors or outdoors. Wi-Fi is ed by many applications and devices • video game consoles • home networks • PDAs • mobile phones • major operating systems • other types of consumer electronics

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2.18.3 Wireless Security A common but unproductive measure to deter unauthorized s is to suppress the AP's SSID broadcast, "hiding" it. This is ineffective as a security method because the SSID is broadcast in the clear in response to a client SSID query. Another unproductive method is to only allow computers with known MAC addresses to the network.MAC address are easily spoofed. If the eavesdropper has the ability to change his MAC address, then he may the network by spoofing an authorized address . Wired Equivalent Privacy (WEP) encryption was designed to protect against casual snooping, but is now considered completely broken. Tools such as AirSnort or aircrack can quickly recover WEP encryption keys. To counteract this in 2002, the Wi-Fi Alliance blessed Wi-Fi Protected Access(WPA)for wireless security. Though more secure than WEP, it has outlived its designed life time, has known attack vectors and is no longer recommended. In 2004 the full IEEE 802.11i(WPA2) encryption standards were released. If used with a802.1Xserver or in pre-shared key mode with a strong and uncommon phrase WPA2is still considered secure, as of 2009.

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3. CONCLUSION General Conclusion Computer Networking is a very vast project in the present developing era of electronics and communication. Now a days, computers are used in a wider range. All the organizations are using multiple computers within their departments to perform their day to day work. Computer network allows the to share data , share folders and files with other s connected in a network. Computer Networking has bound the world in a very small area with it wide networking processes like LAN, MAN, WAN. Applications • • • • • • •

Communication Field Industries Medical Field Research Field Organizations School Colleges

REFRENCES • • • • • • • •

www.google.com www.microsoft.com www.nythimes.com www.digitec-engineers.com Network Essentials module 4-in-1 MCSE study material Introduction to Window server2003 CISCO Certified Network Associate