Rip Problems

Webmonkey

Hi There,

Just doing some lab work on 3 routers (cisco 2600s), 2 of which are connected to a top router via serial cables.
We'll call these 3 routers: Gad, Anniston and Boaz.

Anniston s0/0

---

connected to

---

s0/1 on Gad
Boaz s0/0

---

connected to

---

s0/0 on Gad

Configurations:

Gad

interface Serial0/0
ip address 192.168.1.1 255.255.255.0
no ip directed-broadcast
clockrate 64000
!
interface Serial0/1
ip address 192.168.101.1 255.255.255.0
no ip directed-broadcast
clockrate 64000

Anniston

interface FastEthernet0/0
ip address 172.16.5.126 255.255.255.128
no ip directed-broadcast
!
interface Serial0/0
ip address 192.168.1.2 255.255.255.0

Boaz

interface FastEthernet0/0
ip address 172.16.5.254 255.255.255.128
no ip directed-broadcast
!
interface Serial0/0
ip address 192.168.101.2 255.255.255.0


The Hosts connect with the 172.16.0.0 network. This network is subnetted using 255.255.255.128 or 172.16.0.0/25

I picked a sub network for each of Anniston and Boaz's f0/0 port:

Anniston gets: 172.16.5.0 /25
Boaz gets: 172.16.5.128 /25

(I selected the last IP in the host range as the router/default gateway IP ,f0/0)

Now attached to Anniston and Boaz's f0/0 interface is a simple switch. To this are 2 hosts on each switch.
The hosts get IP's as well:

Annistons two hosts get:
172.16.5.1/25 DGateway: 172.16.5.126
172.16.5.64/25 DGateway: 172.16.5.126

Boaz two hosts get:
172.16.5.129/25 DGateway: 172.16.5.254
172.16.5.192/25 DGateway: 172.16.5.254

Hope i havn't confused you now but this is my basic setup. If you really don't get what the layout here is, i'll throw up a diagram.

Now everything works fine, Hosts can ping gateway, Anniston and Boaz can ping Gad and vice versa.

The problem I have is in the routing, and hopefully someone can see where i going wrong.

Gad's RIP configuration

Gad(config):#router rip
Gad(config-router):#network 192.168.1.0
Gad(config-router):#network 192.168.101.0

Anniston's RIP configuration

Anniston(config):#router rip
Anniston(config-router):#network 172.16.0.0
Anniston(config-router):#network 172.16.0.0

Boaz's RIP configuration

Anniston(config):#router rip
Anniston(config-router):#network 172.16.0.0
Anniston(config-router):#network 172.16.0.0


Now, I amn't sure what is going wrong but i can ping from the hosts on Anniston to the Boaz router, that as far as i can go and same with the other way around. I am totally confused. Only 60% of pings are successful too often when pinging from router to distant router. I am really confused.

When configuring Anniston and Boaz's - am i right on putting the underlining network of 172.16.0.0. Should I put 172.16.5.0 and 172.16.5.128.

Hopefully someone can shead bit of light on this!

Webmonkey

Guess no one out there that can help?
Pinging from Gad to the fast ethernet interfaces of Anniston and Boaz i get:

Gad#ping 172.16.5.126

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.5.126, timeout is 2 seconds:
!U!.!
Success rate is 60 percent (3/5), round-trip min/avg/max = 28/28/28 ms

This happens all the time, and same if I ping 172.16.5.254.

Any ideas?

_CreeD_

In the middle of something but off the top of my head you're using classless subnets, RIP does not support classless/VLSM/CIDR. Try RIP v2 or OSPF/EIGRP

Webmonkey

Have ip classless command used.
I decided to rebuild the whole thing on RouterSim and seems to work. Hope these things don't happen in my lab exam coming up next week now. Cheers for that.

_CreeD_

IP Classless doesn't affect how RIP v1 operates though. It's a fundamental limitation of the routing protocol, it does not advertise subnet masks and assumes Classful rules at all times.

Webmonkey

Sorry just realised that. My network lecture saying RIP v1 should be able to handle this scenario. I don't think so.
Am i right in saying /8 /16 and /24 are classful and rest not?

_CreeD_

Your 192.168.x.0 ranges are fine as the subnet mask matches the class /24 . The 172.16.x.0 are the problem since it should be /16 which will make Boaz and Anniston both advertise that they have all of the 172.16.x.x range locally.
TBH my CCNA stuff is getting rusty (spent much more time lately on the security side) but there is no way I can see that RIP v1 will allow for proper routing with those subnets. As a test try one of the others (excl. IGRP)