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Classful subnetting and RIPv2 routing

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16 years 5 months ago #26518 by sbiangue
Hi,

I have subnetting a class C network (192.168.111.0) into 8 subnets of 30 hosts each ( 192.168.111.0 , 192.168.111.32,...). when I configure RIPv2 on the 1841 router to accept routing between 2 subnets (192.168.111.0 and 192.168.111.32) only one network is accepted in the router configuration(192.168.111.0). what could be the problem? Why the 1841 does not accept the subnet 192.168.111.32?
Please help!

sbiangue.
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16 years 5 months ago #26519 by Chojin
try the 'No auto-summary' command for your RIP v2.

CCNA / CCNP / CCNA - Security / CCIP / Prince2 / Checkpoint CCSA
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16 years 5 months ago #26522 by sbiangue
Thx Chojin,

I have tried to insert the "no auto-summary" command in RIPv2 configuration, no success. The cisco 1841 router wont accept the second subnet (192.168.111.32 255.255.255.224).
But the network 192.168.1.0 255.255.255.0 is accepted. Why is that RIPv2 configuration doesn't accept the two subnets 192.168.111.0/27 and 192.168.111.32/27 comming from 192.168.111.0/24 subnetting?

I will appreciate your help.

Sitas. :cry:
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16 years 5 months ago #26526 by S0lo
Don't worry, it's working as it should. For routing protocols: RIP, RIPv2, IGRP and EIGRP the "network" command is always classfull. When you "show run" or "show start" it will show only the classfull subnetwork address although you have configured a subnet mask of /27. It does not care about it. In other words the following commands are identical:

[code:1]
network 192.168.1.0

network 192.168.1.32

network 192.168.1.64

.....
[/code:1]

They will all sum up to

[code:1]
network 192.168.1.0
[/code:1]

This tells the router to advertise any network with a 192.168.1.x address. Off-course since your using RIPv2 and "no auto-summary" it will always advertise the correct mask (/27).

Studying CCNP...

Ammar Muqaddas
Forum Moderator
www.firewall.cx
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16 years 5 months ago #26533 by sbiangue
Thx Solo,

My RIP confuguration is working, it is considering both subnets ( 192.168.111.0/27 and 192.168.111.32/27), just as you said. The overall network is up and running.

Thank you all!

Sbiangue.
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