Summary Of Routing Protocols

RIP (Routing Information Protocol) 1- Distance Vector Routing Protocol 2-Send Periodic updates every 30 sec out of all its ports on broadcast address 255.255.255.255, updates contains full routing table. 3-Triggered updates is sent at change. 4-Symbol in routing table is “R” 5-Administrative Distance = 120 by default 6-Metric is hop count (max.=15), 16 hop = unreachable 7-Rotuing table is built using Bellman Ford algorithm 8-Support equal load-sharing (load-balancing) 9-Classfull protocol (does not send subnet mask in routing updates), the other end will estimate it 10-use the following solutions to remove loops: - Triggered updates with poisoned route & poison reverse - Split Horizon - Hold Down Timers = 180 sec

IGRP (Interior Gateway Routing Protocol) 1- Distance Vector Cisco Proprietary Routing Protocol 2-Send Periodic updates every 90 sec out of all its ports on broadcast address 255.255.255.255, updates contains full routing table. 3-Triggered updates is sent at change. 4-Sumbol in routing table is “I” 5-Administrative Distance = 100 by default 6-Metric is Composite metric (BW, Delay, Load, Reliability & MTU), default is BW & Delay, hop count (max.=100 by default, but can reach 255 hop by configuration) 7-Rotuing table is built using Bellman Ford algorithm 8-Support equal & unequal load-sharing (load-balancing) 9-Classfull protocol (does not send subnet mask in routing updates), the other end will estimate it 10-use the following solutions to remove loops: - Triggered updates with poisoned route & poison reverse - Split Horizon - Hold Down Timers = 280 sec

RIP v2 1- Advanced Distance Vector Routing Protocol 2-Send Periodic updates every 30 sec out of all its ports on multicast address 224.0.0.9, updates contains full routing table. 3-Support Authentication for incoming updates 4-Classless routing protocol (send subnet mask in updates) 5-Triggered updates is sent at change. 6-Sumbol in routing table is “R” 7-Administrative Distance = 120 by default 8-Metric is hop count (max.=15), 16 hop = unreachable 9-Rotuing table is built using Bellman Ford algorithm 10-Support equal load-sharing (load-balancing) 11-use the following solutions to remove loops: - Triggered updates with poisoned route & poison reverse - Split Horizon - Hold Down Timers = 180 sec

EIGRP Features • Advance Distance Vector Cisco proprietary routing protocol • Maintain neighbor relationship using hello protocol •Send full routing table at start up & triggered partial updates at change •Send updates on multicast address 224.0.0.10 •Support Authentication •Classless routing protocol •Fast convergence, can store Backup path for every best path • Process routing updates using DUAL (Diffusion Update Algorithm) algorithm •Send Query packet to all neighbors in case S fails and no FS maintained in the topology table to inform neighbors that a route get unreachable and ask for another valid route

EIGRP Features (cont.) •symbol D in the routing table •Administrative Distance for Internal routes = 90, External routes = 170 •Differentiate between Internal and External routes •Backward compatible with IGRP (if both in the same AS) •EIGRP metric (32 bit)= 256 x IGRP metric (24 bit), composite metric (BW & delay by default), max hop (default 100, max 224) •Support equal & non-equal loadsharing (loadbalancing) •Support routing for multiple routed protocols IP, IPX, and AppleTalk

EIGRP Terminologies •Neighbor table: List of all neighbors •Rotuing table: List of best paths to destination •Topology Table: List of all paths to destination •Successor S : Is the best route to given destination network, stored in topology table and routing table • Feasible Successor FS : Is a backup route for the Successor for a given destination network, stored in topology table only •Feasible Distance FD : Is the total metric to a given destination network • Advertised Distance AD : Is the metric as it advertised from neighboring router to reach certain network

EIGRP Configuration Example

OSPF Features • Link State routing protocol •Use multicast address for updates 224.0.0.5 & 224.0.0.6 •Maintain neighbor relationship using hello protocol • OSPF depends only on triggered partial updates at change, but sends periodic refreshment for each LSA every 30 min •Support Authentication • Symbol in routing table is O • Administrative Distance = 110 • Metric called cost = 10^8 / BW, default BW on serial =1.54Mbps, hop is unlimited (config)#interface s0 (config-if)#bandwidth bw in units of Kbps •Classless routing protocol •Process routing updates using Dijkstra algorithm •Support Hierarchical design (multiple area )