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New Member

NAT trouble

Hi, I have inherited a system which I am trying to make work. It consists of two routers each with an ethernet and a bri. For some reason this very straightforward network has some NAT. I guess the NAT was configured as a workaround for some old legacy application and migration to a new network or something.

My problem is that the routers dial and ping each other OK without the NAT (removing 'ip nat outside' from dialer 2) but when this is put back on the traffic doesn't pass. Does the NAT pool address range need to match that of the bri at the receiving end? Am I missing some static routes for the pool address?

Help appreciated.

Router configs summerised with the interesting bits only!

Router1. (Dialing end)

eth 0

ip address 192.168.202.191/24

ip nat inside

dialer 2

ip address 192.128.0.50/24

ip nat outside

ip nat pool NATPOOL 192.168.0.112 192.168.0.112 netmask 255.255.255.0

ip nat inside source list 101 pool NATPOOL overload

ip classless

ip route 90.90.91.0 255.255.255.0 dialer 2

access-list 101 permit ip any any

Router 2 (Receiving end)

eth 0

ip address 90.90.91.216 /24

bri0

ip address 192.128.0.2/24

ip route 0.0.0.0 0.0.0.0 bri0

ip route 90.90.90.90 255.255.255.0 bri0 - not sure why this route is here.

1 REPLY
New Member

Re: NAT trouble

There's got to be something missing... Any packet sourced from Router 1's ethernet destined for Router 2 will have its source address NAT'ed to 192.168.0.112. Router 2 would need a route for that network/host to return any packets.

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