nat and vlans on 1841 router

[dennisjohnson104]

i have an old 1605 router that is doing nat for me. e0/0 is my external interface. e0/1 is my internal interface 172.16.0.1 255.255.255.252

i have nat enabled on the router on the 1605r. It works fine when i directly connect a pc to the internal interface.

I have a 1841 router. interface f0/0 172.16.0.2 255.255.255.252 is connected to e0/1 on the 1605r.

Now on the f0/1 of the 1841 i have two subinteraces f0/1.1 10.0.0.1 255.240.0.0

and f0/1.2 192.168.0.1 255.255.255.0

i have dot1q encapsulation on the interfaces with vlan 1/f0/1.1 set to native.

The 2 vlans can talk fine, i can ping each machine on the vlans. But i can only ping as far as 172.16.0.2/ f0/0.

i have a static route set on 1841 router 0.0.0.0 0.0.0.0 172.16.0.1.

Can anyone tell me what im doing wrong.

[Richard Burts]

I believe that the first issue is a routing question on the 1605. When anything on the VLANs of the 1841 attempts to ping to any address on the 1605 the source address of the ping will be 10.0.x.x or will be 192.168.0.x. Is there anything on the 1605 that tells it where this address space is and what interface to use to get to it?

I believe that supplying static routes on the 1605 for ip route 10.0.0.0 255.240.0.0 172.16.0.2 and ip route 192.168.0.0 255.255.255.0 172.16.0.2 will allow devices on the VLANs to ping addresses on the 1605.

If you want the devices on the VLANs to access things beyond the 1605 there is probably another issue. I am guessing that the NAT that you have configured processes the 172.16.0.0 subnet and prbably does not have anything in it about 10.0.0.0 or 192.168.0.0. You will probably have to add to the NAT logic to cover these addresses as well.

HTH

Rick