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Rip - Classful subnets

By neuralping ·
Using Boson NetSim 6 simulator - Lab 6 RIP. The simulator clearly states RIP has to have classful network number. However,There are a couple of classless network numbers being used on routers 3 and 4. Router 3 would not advertise routes when using a classful network of 197.10.0.0. What am I missing. Can rip use classless network numbers?

Router1
network 160.10.0.0
network 175.10.0.0

Router2
network 160.10.0.0

Router3
network 175.10.0.0
network 180.10.0.0
network 197.10.1.0

Router4
network 180.10.0.0
network 195.10.1.0

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Version 2 supports VLSM, & Classless

by CG IT In reply to Rip - Classful subnets

Version 1 doesn't. Version1 is stricktly classful.

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RIP - Classfull subnets

by neuralping In reply to Version 2 supports VLSM, ...

I saw documentation where RIPv1 does not send subnet mask information when advertising routes which is the reason why you need to use classful networks numbers. The strange thing is Router 4 advertising network 195.10.1.0 gets sent out to the other routers with no problem. Just router 3 with network 197.10.1.0 won't advertise when it's classless. I watched using debug ip rip and it never got sent out but on router 4 195.10.1.0 gets advertised.

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Dude RIP1 is classful, period.

by CG IT In reply to RIP - Classfull subnets

RIP version 2 is classless and supports VLSM. So if you have IP classess command in the configuration, use RIP 2 to advertise.

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RIP - Classless networks

by neuralping In reply to Dude RIP1 is classful, ...

OK. I got it. Thanks for the help.

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RIP - Classles networks

by neuralping In reply to RIP - Classfull subnets

I also noticed both networks are ethernet.

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Could you explain

by NetMan1958 In reply to Rip - Classful subnets

Why you say "However, There are a couple of classless network numbers being used on routers 3 and 4"

I'm not saying you are wrong as I don't have that NetSim you are using so I can't see everything you see. I am curious though.

Also, you might be interested in this article:
http://www.cisco.com/application/pdf/paws/13724/55.pdf

The take-away is that if RIPv1 advertises a route across a major network boundry then it automatically summarizes it. However, if it advertises the route across a link that is part of the same major network, then it sends the subnet mask also.

For example:
172.16.1.0/24 -> 172.20.1.0/24 -> 172.16.2.0/24
The router advertising 172.16.1.0/24 summarizes the route to 172.16.0.0

However:
172.16.1.0/24 -> 172.16.3.0/24 -> 172.16.2.0/24
The router advertising 172.16.1.0 sends the route as 172.16.1.0 255.255.255.0

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Guy mentioned Classless RIPv1 is classful

by CG IT In reply to Could you explain

if he's doing VLSM, RIPv2

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