Allowing ports on cisco 837

Cisco devices usually only ship with a barebones basic installation manual (ie. how to plug the cables in), because the CLI command set of IOS takes up a full bookshelf printed out.

The last time I remember getting a full set of manuals with the device was with 9.x, for 10.x we had to ask for them. But all their docs are online on their website for any level of depth you want to investigate.

You don't really say what your configuration is. (Cisco also doesn't come with a preset config, usually the installer does it all up from scratch).

I'm assuming some sort of NAT setup, and you want to map port 22 of your single public IP on through to the inside?

Something like

ip nat inside source static tcp 192.168.0.1 22 198.198.198.198 22 extendable

should be added to your static NAT list to map from outside to inside.

Thanks Doug, that has helped a bit. Just one question... the numbers

192.168.0.1 and 198.198.198.198, how did you get them? I have had a look on the cisco website. Im not familiar with configs of the modem. I didnt set it up, and i dont know how to retreive it. The whole reason i need to do this is because i cant setup the hardware spam filter without opening port 22 - the web based config of the spam filter needs this open.

i know the ip address of the modem is 192.168.1.3

im pretty sure thats what i need to do.

Thanks Simon

They are made up.

192.168.0.1 is theoritically some internal private IP of your server that you need to do port forwarding into from the outside. 198.198.198.198 is theoritically your external public IP address.

check out

Its got a config wizard for the 837 and some good articles on the basics of setting up cisco routers