DDNS on WRT54G2

[dbeaujon]

Hi,

I have a very annoying problem with a WRT54G2 v.1. This is my configuration:

I have a cable modem with NAT giving out IP's on the range 192.168.0.x/C

The DHCP range is from 10 to 20. The internal IP address of the cable modem is 192.168.0.1/C

I have connected the WRT54G2 internet interface to this network and assigned it the IP address 192.168.0.2/C.

On the internal interface of the WRT54G2 I have assigned the IP address 192.168.10.1/C with the DHCP range from 10 to 20.

I can access the Internet with no problem. When I configure the DDNS on the WRT54G2 using DynDNS it also works but I get the external IP address of the WRT54G2, in other words 192.168.0.2. For some reason the WRT54G2 will not apply the external IP address of my cable modem (my real internet IP address) to the DynDNS address. I have tried to change WRT54G2 external interface configuration from Static IP address and Dynamic IP address but with the same results. Can anybody tell me how to make this work?

Thanks,

dbeaujon

[kevj]

If you Cable modem/gateway supports DDNS updates, that is where you should configure DDNS..not on the WRT

[dbeaujon]

That's exactly the reason why I got the WRT54G2, because the cable modem does not have a DDNS option in it's configuration.

[kevj]

What model is the cable gateway? You may need to find out if you can put it in Bridge mode to bypass the NAT/router portion of it, and just use the modem part, then use the WRT as your Internet gateway. If you can do that, you should get a public IP on the WAN interface of your WRT and DDNS should work OK.

[dbeaujon]

I have also researched the modem and there no bridge mode in it. It only works through NAT. It is a motorola cable modem with wireless integrated. I'm not on premisses right now that I can check the model number.

[kevj]

If the modem cannot be bridged, then the only solution to this may be 3rd Party firmware on the WRT (which is what most people buy WRT54GL's for anyway).

Tomato (www.polarcloud.com/tomato) has an option in the DDNS setup to verify Dynamic DNS using an external IP address checker, rather than relying on the WAN interface to be correct (for situations just such as yours). 

Be advised that installing 3rd party firmware will void any warranty you have with Linksys...