I'm trying to get my head around RIP v1 and how it doesn't work with classless networks. I understand classful vs classless networks, but I cannot seem to create a router configuration that will not work with RIP v1. Admittedly I have spent more time googling for an answer than actually playing with the routers...
Can someone please give me an example of a network configuration that would not work with RIP v1? This should help me understand what is going on.
Thanks,
All /24.........
10.1.1.0-------router----200.200.200.0----router---100.100.100.0---router---10.2.2.0The router in the middle doesn't know how to reach the 10.1.1.0 and 10.2.2.0 subnets. The poor fellow is confused. His route table says 10.0.0.0 is available via the East and the West.
Have fun!
-ja
10.1.1.0-------router----200.200.200.0----router---100.100.100.0---router---10.2.2.0
"no auto-summary" under the RIP processes on the edge routers would cause this, but I suspect you see what you see is probably because you are on a router "SIM" and not a real router.....
Simulators don't act like real routers; they only do whatever 'canned' stuff was written into them, and usually leave a lot to be desired....
-ja
10.1.1.0-------router----200.200.200.0----router---100.100.100.0---router---10.2.2.0
John,
I have implemented this network as you have described, and I understand that the middle router should be confused about the 10.1.1.0 and
10.2.2.0 networks because the classful network number for both is 10.0.0.0.However, when I implemented this using RouterSim, the middle router was still populated with the correct entries, i.e.
network 10.0.0.0 is subnetted, 2 subnets
10.1.1.0 via 200.200.200.2 10.2.2.0 via 100.100.100.1Is this happening because the ip classless option is enabled? I tried turning it off but the command doesn't work - I think I need to update RouterSim.
I can give this a try on the real hardware tomorrow...
OK, that makes sense to me now. Thanks John! As for RouterSim - it looks like no auto-summary is the default setting and there is no way to switch it on - the command isn't implemented for RIP in the version I'm using. However, the command is implemented for EIGRP, so I could at least use that and get a better feel for what was going on.
I'm thinking about getting a couple of routers for home but, as ever, spare cash is a limiting factor. Luckily I work at a University that has a Cisco lab that I can use, and RouterSim that I can use remotely from home.
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