{"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
Feature<\/th>\n
RIP (Default)<\/th>\n
IGRP (Default)<\/th>\n<\/tr>\n
\n
Update Timer<\/td>\n
30 sec<\/td>\n
90 sec<\/td>\n<\/tr>\n
\n
Metric<\/td>\n
Hop Count<\/td>\n
Function of bandwidth and delay (the default). Can include reliability, load, and MTU.<\/td>\n<\/tr>\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
Sends and receives ICMP echo messages to verify connectivity.<\/td>\n<\/tr>\n
\n
trace [protocol<\/i>] [destination<\/i>]<\/td>\n
Sends 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
\n
The router broadcasts or multicasts routing updates out an interface.<\/li>\n
The router listens for incoming updates on that same interface.<\/li>\n
The router, when sending an update, includes the subnet off that interface in the routing update.<\/li>\n<\/ul>\n
The router matches interfaces with the network command by asking this simple question:<\/p>\n
“Which of my interfaces have IP addresses with the same network number referenced in this network subcommand?”<\/p>\n
For all interfaces that match the network command, the router does the three things just listed.<\/p>\n
Here are the examples of configuring RIP and IGRP on the routers, shown on the following known picture:<\/p>\n
<\/p>\n
RIP Configuration<\/h2>\n
Router R1:<\/p>\n
...<\/code><\/p>\n
! \nrouter rip \nnetwork 10.0.0.0 \n!<\/p>\n
…<\/p>\n
R1#sh ip route \nCodes: C – connected, S – static, R – RIP, M – mobile, B – BGP \nD – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area \nN1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2 \nE1 – OSPF external type 1, E2 – OSPF external type 2 \ni – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2 \nia – IS-IS inter area, * – candidate default, U – per-user static route \no – ODR, P – periodic downloaded static route<\/p>\n
Gateway of last resort is not set<\/p>\n
10.0.0.0\/24 is subnetted, 4 subnets \nC\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.1.0 is directly connected, FastEthernet0\/0 \nR\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.2.0 [120\/1] via 10.10.1.2, 00:00:19, FastEthernet0\/0 \nR\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.3.0 [120\/2] via 10.10.1.2, 00:00:19, FastEthernet0\/0 \nR\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.10.0 [120\/2] via 10.10.1.2, 00:00:19, FastEthernet0\/0 \nR1# \nR1#ping 10.10.3.3<\/p>\n
Type escape sequence to abort. \nSending 5, 100-byte ICMP Echos to 10.10.3.3, timeout is 2 seconds: \n!!!!! \nSuccess rate is 100 percent (5\/5), round-trip min\/avg\/max = 108\/159\/264 ms \nR1#<\/p><\/blockquote>\n
Router R2:<\/p>\n
...<\/code><\/p>\n
! \nrouter rip \nnetwork 10.0.0.0 \n!<\/p>\n
…<\/p>\n
R2#sh ip route \nCodes: C – connected, S – static, R – RIP, M – mobile, B – BGP \nD – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area \nN1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2 \nE1 – OSPF external type 1, E2 – OSPF external type 2 \ni – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2 \nia – IS-IS inter area, * – candidate default, U – per-user static route \no – ODR, P – periodic downloaded static route<\/p>\n
Gateway of last resort is not set<\/p>\n
10.0.0.0\/24 is subnetted, 4 subnets \nC\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.1.0 is directly connected, FastEthernet0\/0 \nC\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.2.0 is directly connected, Serial1\/0 \nR\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.3.0 [120\/1] via 10.10.2.1, 00:00:14, Serial1\/0 \nR\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.10.0 [120\/1] via 10.10.2.1, 00:00:14, Serial1\/0 \nR2#<\/p><\/blockquote>\n
Router R3:<\/p>\n
...<\/code><\/p>\n
! \nrouter rip \nnetwork 10.0.0.0 \n!<\/p>\n
…<\/p>\n
R3#sh ip route \nCodes: C – connected, S – static, R – RIP, M – mobile, B – BGP \nD – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area \nN1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2 \nE1 – OSPF external type 1, E2 – OSPF external type 2 \ni – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2 \nia – IS-IS inter area, * – candidate default, U – per-user static route \no – ODR, P – periodic downloaded static route<\/p>\n
Gateway of last resort is not set<\/p>\n
10.0.0.0\/24 is subnetted, 4 subnets \nR\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.1.0 [120\/2] via 10.10.3.1, 00:00:10, Serial1\/0 \nR\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.2.0 [120\/1] via 10.10.3.1, 00:00:10, Serial1\/0 \nC\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.3.0 is directly connected, Serial1\/0 \nR\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.10.0 [120\/1] via 10.10.3.1, 00:00:10, Serial1\/0 \nR3#<\/p><\/blockquote>\n
Router R:<\/p>\n
...<\/code><\/p>\n
! \nrouter rip \nnetwork 10.0.0.0 \n!<\/p>\n
…<\/p>\n
R#sh ip route \nCodes: C – connected, S – static, R – RIP, M – mobile, B – BGP \nD – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area \nN1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2 \nE1 – OSPF external type 1, E2 – OSPF external type 2 \ni – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2 \nia – IS-IS inter area, * – candidate default, U – per-user static route \no – ODR, P – periodic downloaded static route<\/p>\n
Gateway of last resort is not set<\/p>\n
10.0.0.0\/24 is subnetted, 4 subnets \nR\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.1.0 [120\/1] via 10.10.2.2, 00:00:01, Serial1\/0 \nC\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.2.0 is directly connected, Serial1\/0 \nC\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.3.0 is directly connected, Serial1\/1 \nC\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a010.10.10.0 is directly connected, FastEthernet0\/1 \nR#<\/p><\/blockquote>\n
IGRP Configuration<\/h2>\n
You configure IGRP just like RIP, except that the router igrp command has an additional parameter-the autonomous system (AS) number. The term autonomous system refers to a network that is within the control of a single company or organization. The term AS number refers to a number assigned to a single company or organization when it registers its connection to the Internet. However, for IGRP, you do not need a registered AS number. All that is needed for IGRP to work is for all the routers to use the same AS number.<\/p>\n
IGRP configuration begins with the router igrp 1 global configuration command. Then four consecutive network commands match all the interfaces on the router so that IGRP is fully enabled. In fact, these network commands are identical to the network commands in the complete RIP configuration.<\/p>\n