R O U T I N G , B R O A D C A S T I N G A N DM U L T I C A S T I N GComputer Network
IP addresses Every computer has a physical address which iscalled as MAC address(LAN Card address/hardwareaddress) or NIC card address, this address is 48 bitaddress. Communication in internetworking is not possiblewith the MAC address, because computermanufactured by different companies and they don’tfollow the same format of generating the MACaddress. General MAC address format1. 00-10-FA-6E-38-4A OR 2. 50-1A-DE-90-42-DC
IP address There will be a IANA(Internet Assigned numberauthority)(www.iana.org). These are generally assigned alogical addressing system(called as ip address) and in systemits store in Cache memory. A system in networking world is identify by ip address. The designer of internet protocol define as an ip address as a32 bit number and this system is known as IPV4 (internetprotocol version 4) is still we use today. However due to theenormous growth of internet and predicteddepletion(decrease) of available addresses a new version IPV6using 128 bit for the address was developed in 1995. Ipv4 address are 172.16.254.1 Ipv6 address are 2001:db8:0:1234:0:567:8:1
Classification of computer network by ip address Classes are generally divided into two parts:1. Net Id. (32 bit)2. Host Id. Classes are divided into five classes:1. Class A- unicasting.2. Class B- unicasting.3. Class C- unicasting.4. Class D-Multicasting.5. Class E- Research work.
Class A: 0 (2^7-2) (2^24-2)(8 bits) Net ID Host ID (24 bits)As octet value of class A is (0-127). There will be a specialaddress (0.0.0.0) which is a default address or the DHCPclient(Dynamic Host Configuration protocol).127.x.y.z it is a Loop back address. Where x,y,z is from (0-255).Number of network= 2^7-2= 128-2=126. So the range ofclass A is (1-126) and each network have host id (2^24-2).* Network Mask : 255.0.0.0
Class B: 10 2^14 (2^16-2)(16 bits) Net ID Host ID (16 bits)The range of ip address is (128-191). There will be nospecial address.Number of networks = 2^14.* Network Mask: 255.255.0.0 Class C: 110 (2^21) (2^8-2)Net ID(24 bits) Host ID(8 bits)The range of class C is (192-223). There will be also nospecial address.* Network Mask: 255.255.255.0 (Default Mask)
Class D: During unicasting we require Net id andHost Id where as during Multicasting we don’trequire Net id and Host id.1110The Range is from(224-239). Class E: This is for research area.1111The range is from (240-254), 16.257.11.13 is a wrongip address because 257 is not a valid address.
Calculating the Net id and Host id withNetwork mask 22.214.171.124 calculate the net id?126.96.36.199 63: 00111111255.0.0.0 255:1111111188.8.131.52 (Net id) :0011111* 184.108.40.206 is the direct broadcast address.Net ID220.127.116.11Net ID18.104.22.168Host ID22.214.171.124Host ID126.96.36.199Host ID188.8.131.52
Characteristic of loop back address It is used to test if the ip address packets are comingfrom the other system or going out of the system. Physical port are used to transfer the data. Loop backaddress will always used as a destination address. Itis used for inter process communication with in thesame system. In class A 126 network have 2^24-2 host whichapprox 80,00,00 host if we use only 15000 then thelarge number of ip address are going to be waste. Sothis will be use in multinational company use.
And in class B 2^14 network each network have(2^16-2) host 65,534 host here also the ip addressare waste. Class C have 2^21 network and each network have(2^8-2)= 254 hosts. So that in institution and smallcompanies are used this because the ip address arenot to be wasted over this.
Router Router is a WAN device(where different LANnetwork are connected). Connecting to different router with different modelnetwork we use GATEWAY. Suppose we use TCP/IPmodel network and X.25 model network. We usegateway to communicate with these two routers.
Router sending and receiving Data| 184.108.40.206 (SIP) | 220.127.116.11(DIP). In this thedata is transmit to class A to class B. Data| 18.104.22.168 (SIP) | 22.214.171.124(DIP). In this thedata is send and receive to same class A this is calledas a unicasting. Data| 126.96.36.199 (SIP) | 255.255.255.255 (DIP). Inthis the DIP is the limited broadcast address. Whichbroadcast with in the network of Class A. Data| 188.8.131.52 (SIP) | 184.108.40.206 (DIP). In thisclass A send the data to broadcast to all the networkclass B.
Working of Ping? When you start window-> goto command promptand Run cmd. This will be you see:C:>ping 220.127.116.11 Enter.Ping (packet internet grapher). Ping is a clientto server utility that is provided by operating system.C:> ping 18.104.22.168 EnterTTL=2 MS RTT=4MSC:> ping 22.214.171.124 EnterDestination unreachable(DIP is not configure)
TTL is time to line, Its going to indicate the no. ofhops the packets are traverse before reaching thedestination. Distance from one router to another router is called 1HOP. RTT is Round Trip Time; Time taken for the data toreach the destination and coming back onacknowledgement to the centre.
How to transmit the data and calculate the time Suppose if the size of the message is 1 KB. AndBandwidth is 1 Mbps then the transmission time;TT= (1*10^3 ) B / (1*10^6) bits per sec= 8*10^-3 sec= 8 millisec. Propagation time= Distance/ Velocity. Acknowledgement size<< message size. TT ack= ack size/bandwidth. TT ack<< TT msg data.
PT ack= distance/ velocity. Total time= TT data + PT data + TT ack + PT ack.TT ack is negligible.Total time= TT data + 2*PTRTT(Round Trip Time) =2*PTLink Utilization of sender= TT/ (TT data + 2*PT)
Routing Algorithm Static Algorithm: These are the algorithm whichdoesn’t take the network load as consideration.* Flooding is as a static algorithm. Dynamic Algorithm: The algorithm that containnetwork load as consideration. 1. If the routing of packets are done with in theautonomous system, it is known as inter routingprotocol; example : Distance vector routing algorithm,Link State routing algorithm. 2. If the routing of packets are done betweenautonomous system is known as inter domain routingalgorithm. Example : Path vector routing algorithm.
Distance Vector Routing AlgorithmACBDFEVectortableNewroutingtablePackettransfer torouter A
Linked State Routing AlgorithmD E FGCBA23 4552413
Shortest path tree from Router AD E FGCBA23 4521
Conclusion Computer network is the very large area. Andgenerally we want a network which have a highspeed of transmission and very less of error whilecommunicating. Computer network wants speed,accuracy, adequacy and security. These are the allfuture aspects of computer network which we willhave to consider.