{"id":114,"date":"2014-02-25T21:10:18","date_gmt":"2014-02-25T21:10:18","guid":{"rendered":"https:\/\/learncisco.net\/index.php\/rip-and-igrp\/"},"modified":"2023-01-10T04:43:15","modified_gmt":"2023-01-09T21:43:15","slug":"rip-and-igrp","status":"publish","type":"page","link":"https:\/\/www.learncisco.net\/courses\/cisco-ccna\/ip-routing-technologies\/rip-and-igrp.html","title":{"rendered":"RIP and IGRP"},"content":{"rendered":"

RIP and IGRP have many similarities in their general logic but several differences in the details of their implementation.<\/p>\n\n\n\n\n\n\n\n\n\n
Feature<\/th>\nRIP (Default)<\/th>\nIGRP (Default)<\/th>\n<\/tr>\n
Update Timer<\/td>\n30 sec<\/td>\n90 sec<\/td>\n<\/tr>\n
Metric<\/td>\nHop Count<\/td>\nFunction of bandwidth and delay (the default). Can include reliability, load, and MTU.<\/td>\n<\/tr>\n
Hold-down Timer<\/td>\n180 sec<\/td>\n280 sec<\/td>\n<\/tr>\n
Flash (Triggered) Updates<\/td>\nYes<\/td>\nYes<\/td>\n<\/tr>\n
Mask Sent in Update<\/td>\nNo<\/td>\nNo<\/td>\n<\/tr>\n
Infinite-Metric Value<\/td>\n16<\/td>\n4 294 967 295<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

The IGRP metric provides a better measurement of how good a route is, as compared with RIP’s metric. IGRP’s metric is calculated using the bandwidth and delay settings on the interface on which the update was received. When bandwidth and delay are used, the metric is more meaningful than hop count; longer hop routes that go over faster links are considered better routes by IGRP.<\/p>\n

RIP uses hop count as its metric. When an update is received, the metric for each subnet in the update signifies the number of routers between the router receiving the update and each subnet. Before sending an update, a router increments by 1 its metric for routes to each subnet.<\/p>\n

Finally, the issue of whether the mask is sent is particularly important if variable-length subnet masks (VLSMs) in the same network are desired. Neither RIP or IGRP support VLSM.<\/p>\n

The key to configuring RIP and IGRP is to master the use of the network command. Other than that, configuration is relatively easy. You should also know the more-popular show and debug commands, which help you examine and troubleshoot routing protocols.<\/p>\n

The following table summarize the more popular commands used for RIP and IGRP configuration and verification.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Command<\/th>\nConfiguration Mode<\/th>\n<\/tr>\n
router rip<\/td>\nGlobal<\/td>\n<\/tr>\n
router igrp\u00a0as-number<\/i><\/td>\nGlobal<\/td>\n<\/tr>\n
network\u00a0net-number<\/i><\/td>\nRouter subcommand<\/td>\n<\/tr>\n
passive-interface [default] {interface-type interface-number<\/i>}<\/td>\nRouter subcommand<\/td>\n<\/tr>\n
maximum-paths\u00a0number-paths<\/i><\/td>\nRouter subcommand<\/td>\n<\/tr>\n
variance\u00a0multiplier<\/i><\/td>\nRouter subcommand<\/td>\n<\/tr>\n
traffic-share {balanced | min<\/i>}<\/td>\nRouter subcommand<\/td>\n<\/tr>\n
show ip route [ip-address<\/i>\u00a0[mask<\/i>] [longer- prefixes]]| [protocol<\/i>\u00a0[process-id<\/i>]]<\/td>\nShows the entire routing table, or a subset if parameters are entered.<\/td>\n<\/tr>\n
show ip protocols<\/td>\nShows routing protocol parameters and current timer values.<\/td>\n<\/tr>\n
debug ip rip<\/td>\nIssues log messages for each RIP update.<\/td>\n<\/tr>\n
debug ip igrp transactions [ip-address<\/i>]<\/td>\nIssues log messages with details of the IGRP updates.<\/td>\n<\/tr>\n
debug ip igrp events [ip-address<\/i>]<\/td>\nIssues log messages for each IGRP packet.<\/td>\n<\/tr>\n
ping [protocol<\/i>\u00a0| tag] {host-name<\/i>\u00a0|system-address<\/i>}<\/td>\nSends and receives ICMP echo messages to verify connectivity.<\/td>\n<\/tr>\n
trace [protocol<\/i>] [destination<\/i>]<\/td>\nSends a series of ICMP echoes with increasing TTL values to verify the current route to a host.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Each\u00a0network<\/b>\u00a0command enables RIP or IGRP on a set of interfaces. This command “matches” one or more interfaces on a router. For each interface, the network command causes the router to do three things:<\/p>\n