Wednesday, November 9, 2011

Cisco 870 and DynDNS

My gateway to the Internet is a small Cisco 870. I also have a linux host I use to ssh into my home network. The Internet connection is a basic DSL, with a dynamic address.

Before my Cisco router, I used to have a small Netgear gateway that supports DynDNS. So, I wanted to do the same with the cisco router.

Here is the configuration I use:

DynDNS updater

ip ddns update method DynDNS
 HTTP
  add http://<username>:<password>@members.dyndns.org/nic/update?hostname=<hostname>
 interval maximum 1 0 0 0
 interval minimum 0 2 0 0

You have to replace the values between <> with your own, such as your username and password. Also, to insert the "?", press [CTRL]-[v] before the ?. Unfortunately, in version 12.4(15), HTTPS is not supported to update the record.

Interface configuration


 ip ddns update hostname <hostname>
 ip ddns update DynDNS

And that's it. It should start updating your records. However, at least in my case, this wasn't working. A quick debug session showed that "members.dyndns.org" was not resolved by the device, which I solved temporarily with a host entry.

ip host members.dyndns.org 204.13.248.111


Everything is now working fine, and my records are updated.

Edit

I removed the minimum and set the maximum to a lower value.