Bridging Class A and Class C on a 3620

[rboileau]

I have two networks in the same area, one a class C (200.200.200.0/29) and the other a class A (10.1.1.0/24). I currently am bridging these two with a generic "router" from Wal Mart (Linksys).

My goal is to eliminate the Linksys hardware and move both LANs to my 3620 series router. The 200.200.200.0 net is used for a classroom environment for their training, while the 10.1.1.0 is my schoolhouse LAN with a gateway (10.1.1.6) to an ISP.

I have e0/0 configured as 200.200.200.20 255.255.255.248 to handle the classroom traffic, and e0/3 configured as 10.1.1.110 255.255.255.0 for the schoolhouse net. From the router itself, I can traffic either without difficulty. However, nothing off of the 200.200.200.0 network can bridge to the 10.1.1.0 network.

I know I'm missing something simple in my setup, but cannot for the life of me figure out what it is. Any ideas out there?

[jolmo]

Here you are a link for configuring bridging between VLANs:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1834/products_feature_guide09186a008008019c.html#1028669

HTH

[Harold Ritter]

Did you configure a default gateway on devices on each network?

If so, make sure that "ip routing" is configured in global configuration mode on your router.

Hope this helps,

[ziutek · Accepted solution]

If you have the default gateways configured correctly, for exampl the devices on the 200.200.200.0 net pointing to the 200.200.200.20 router interface, and the devices on the 10.1.1.0 network pointing to the 10.1.1.110 router interface, and some time of routing involved, static to the two networks, and default out the 10.1.1.6 interface, then your problems should be solved.

[Harold Ritter]

There is no need to add any routing protocol or to configure static routes since the router sees these subnets as connected.

My 2 cents,

[rboileau]

Thanks Ziutek, that was exactly the problem. I only had the one gateway pointing to the 10.1.10 network!

Thanks to everyone for posting their thoughts here. I was trying to do it in a much more difficult way, by trying to bridge the two together on the router.