CS 350 Chapter-9,10

Implementation of Connectionless Service Routing within a datagram network ISP’s equipment A’s table (initially) A’s table (later) C’s Table E’s Table

Implementation of Connection-Oriented Service Routing within a virtual-circuit network ISP’s equipment A’s table C’s Table E’s Table

Comparison of Virtual-Circuit and Datagram Networks Comparison of datagram and virtual-circuit networks

The IP Routing Process IP address, Mac addressIP address, Mac address

Routing Protocols Routing Static Routing Dynamic Routing IGP EGP Protocols: BGP Distance Vector Protocols: RIPv1&2, IGRP Link State Protocols: OSPF, IS-IS Hybrid Protocols: EIGRP

Default Administrative Distance Route SourceDefault AD Connected interface0 Static route1 EIGRP90 IGRP100 OSPF110 RIP120 External EIGGRP170 Unknown255(this route will never be used)

(a) A network. (b) Input from A, I, H, K, and the new routing table for J. Distance Vector Routing

The Count-to-Infinity Problem The count-to-infinity problem

Link State Routing 1.Discover neighbors, learn network addresses. 2.Set distance/cost metric to each neighbor. 3.Construct packet telling all learned. 4.Send packet to, receive packets from other routers. 5.Compute shortest path to every other router.

Building Link State Packets (a) A network. (b) The link state packets for this network.

Distributing the Link State Packets The packet buffer for router B in previous slide

RIPv1RIPv2 Distance vector Maximum hop count 15 ClassfulClassless Broadcast basedUses Multicast No support for VLSMSupports for VLSM No AuthenticationAllow for MD5 authentication No support for discontiguous networks Supports discontiguous networks

CharacteristicOSPFRIPv2RIPv1 Type of protocolLink stateDistance vector Classless supportYes No VLSM supportYes No Auto summarizationNoYes Manual summarization YesNo Discontiguous support Yes No Rout propagationMulticast on change Periodic multicast Periodic broadcast

CharacteristicOSPFRIPv2RIPv1 Path metricBandwidthHops ConvergenceFastSlow Peer authenticationYes No HierarchicalYes (using area) No (flat only) UpdateEvent triggered Rout table updates Rout computationDijkstraBellman-Ford

Hierarchical Routing Hierarchical routing.