Cisco 878 port forwarding not working

beheer · ‎08-28-2006

I've configged ports to map for smtp, http, ftp, pop3 and https.

When telnetting to the router and checking on the router with show ip nat translation, the correct mappings are made.

The telnet session with the machine behind the router is not established however.

Telnetting from the router to the same machine on the correct ports does work.

At first I thought it was a config error, but the ip nat config is working fine on other routers.

I then put the config on a new 878, thinking some hardware problem. That didn't help, so I'm back at thinking it's a config error.

See attached file for logging and ip nat output as well as config.

Many thanks in advance.

Wouter

globalnettech · ‎08-28-2006

Hello,

try and add the keyword 'extendable' to the end of your static NAT translations, and see if that makes a difference, e.g.:

ip nat inside source static tcp 192.168.10.49 5044 interface Dialer0 5044 extendable

Regards,

GNT

beheer · ‎08-29-2006

To bad, extendable doesn't stick in this ios.

In which version is this option used?

Regards

Wouter

froggy3132000 · ‎09-04-2006

on the vlan 1 interface you have the following:

ip address secondary

is this public range the same as your dsl interface range?

beheer · ‎09-04-2006

No, the ranges are not the same. That is, they share the same B-class stats, but no C-class.

Incidentally, the extendable parameter is present in this ios version. When I change the parameter interface dialer0 to the ip address associated with the interface, extendable is addedd automatically. No joy however.

Today I'm going to try and downgrade the ios, another router with 12.4(4)T1 does have functional port mappings....

beheer · ‎09-11-2006

Thanks everybody.

The problem has been solved.

It turns out the customer had misconfigured their gateway settings on the servers handling the services. Replies never reached the router, if their source ip was internetbound.