Here is my dilemma. I have a rou

[cmorales]

Here is my dilemma.

I have a router that is not keeping the RIP entry. I configured router rip but when I "show ip route" it only displays the directly connected networks.

Any ideas on what could cause this.
All the configrations are set correctly:

 

[gunthnp]

run debug are you reciveing routing updates

gunthnp

 

[gunthnp]

run debug are you reciveing routing updates


gunthnp

 

[Whoheard]

From your question, it sounds like you only have one router. Did you add routes? Are there other routers to get updates from--neighbors? Need more info.

bob

 

[Whoheard]

Can you post the portion of config showing rip and interface info? Expandon the network layout if you could.

bob

 

[tschouten]

I'm going to try to make this as breif as I can.

Rip runs off of Classful Boundaries. If you have broken the classful boundary rip will not update the routes outside this boundary. For example, Say you have a set of interfaces with ip addresses 10.3.1.1 and 10.30.1.1. These are directly connected to the router, you're running RIP with network 10.0.0.0 and network 172.0.0.0. You are connected to another router Running rip with an address of 172.3.1.1 and it is set to the same networks.

You look at the router with the 10.3.1.1 ip address' routing table and only see the interfaces you setup on it and nothing from 172.0.0.0. Why is this happening you ask yourself...answer 10.0.0.0 and 172.0.0.0 are different class boundaries. For these two boundaries to begin talking to each other you would need to create a static ip route pointing to each other on both routers.

I know my explenation was cut-back quite a bit but I hope it helps. I am assuming this is what happend in your case I could be wrong.

 

[irasman]

Whew

http://www that

was a smoker. The prevouos posters are probably more correct debug ip rip to see if your getting updates. If router a is connected to router b the best rout is going to be the directly connected interface.
configuration

...Router one advertising a route for 192.168.1.0 We determine by using the command sh ip prot. Sh ip route could be used to display the currnet routing table see next

p1r1#sh ip prot
Routing Protocol is "rip"
Sending updates every 30 seconds, next due in 20 seconds
Invalid after 180 seconds, hold down 180, flushed after 240
Outgoing update filter list for all interfaces is
Incoming update filter list for all interfaces is
Redistributing: rip
Default version control: send version 1, receive any version
Interface Send Recv Key-chain
Serial0 1 1 2
Routing for Networks:
192.168.1.0
Routing Information Sources:
Gateway Distance Last Update
Distance: (default is 120)

p1r1#sh ip rou
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B -
BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candida
te default
U - per-user static route, o - ODR

Gateway of last resort is not set

172.16.0.0/24 is subnetted, 2 subnets
C 172.16.10.0 is directly connected, Loopback0
C 172.16.11.0 is directly connected, Loopback1
10.0.0.0/24 is subnetted, 1 subnets
C 10.3.3.0 is directly connected, Serial2
C 192.168.1.0/24 is directly connected, Serial0

........Router one is conencted to router 2 via serial0 we discover this by using the comand sh cdp nei det
CDP is a layer 2 protocol and is not dependant on layer 3 configuration.
Device ID: p1r2
Entry address(es):
IP address: 192.168.1.18
Platform: cisco 2500, Capabilities: Router
Interface: Serial0, Port ID (outgoing port): Serial0
Holdtime : 157 sec

Version :
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-JS-L), Version 12.0(26), RELEASE SOFTWA
RE (fc1)
Copyright (c) 1986-2003 by cisco Systems, Inc.
Compiled Mon 31-Mar-03 17:37 by srani

.......So you can see that r2 is connected to r1 and they are both on the same network.
...Use ping.

p1r1#ping 192.168.1.18

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.18, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/32/36
ms
........Now lets take a look at r2

p1r2#sh ip prot
Routing Protocol is "rip"
Sending updates every 30 seconds, next due in 10 seconds
Invalid after 180 seconds, hold down 180, flushed after 240
Outgoing update filter list for all interfaces is
Incoming update filter list for all interfaces is
Redistributing: rip
Default version control: send version 1, receive any version
Interface Send Recv Key-chain
Serial0 1 1 2
Routing for Networks:
192.168.1.0
Routing Information Sources:
Gateway Distance Last Update
192.168.1.17 120 00:07:28
Distance: (default is 120)
.....You can see that r2 is routing for 192.168.1.0
.....Now we get to the problem assuming you have 2 routers you do not see a rip generated route because the directly connected interface has the lowest possible administrative cost the rip route is not a option. Take a look at sh ip prot and you will see what is being routed for. Debug ip rip events and you will see the update process.

.....So using 2 routers how do we propogate routes?
Lets go back to r1
...Configura a loopback interface and route for that interface.

conf t
int lo1
ip address 172.16.10.100 255.255.255.0
router rip
network 172.16.0.0 (rip summarizes by default)

..... You see with sh ip prot that r1 is now routing for 2 netwoks
p1r1#sh ip prot
Routing Protocol is "rip"
Sending updates every 30 seconds, next due in 8 seconds
Invalid after 180 seconds, hold down 180, flushed after 240
Outgoing update filter list for all interfaces is
Incoming update filter list for all interfaces is
Redistributing: rip
Default version control: send version 1, receive any version
Interface Send Recv Key-chain
Loopback0 1 1 2
Loopback1 1 1 2
Serial0 1 1 2
Routing for Networks:
172.16.0.0
192.168.1.0
Routing Information Sources:
Gateway Distance Last Update
192.168.1.18 120 00:16:39
Distance: (default is 120)

....R2 now has a route to the 172 network propogated with rip.
p1r2#sh ip rou
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B -
BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candida
te default
U - per-user static route, o - ODR

Gateway of last resort is not set

R 172.16.0.0/16 [120/1] via 192.168.1.17, 00:00:17, Serial0
C 192.168.1.0/24 is directly connected, Serial0
p1r2#
.....Wala need more routers not a problem I rent for 1.00 per hour 4 hour blocks.

 

[Whoheard]

Very nice! Great insight! I like the explanation. I have attended a bunch of Cisco courses, and I have never heard that before. I will keep that one in mind.

Can I assume this is the result of no other interfaces being configured on the two routers? And, the reason you configured the loopback was to have something else to propagate to the other router?

bob

I know what I know and that's all I know.