3com wireless Cable/DSL gateway and DNS

[shaglund]

I have just set up a 3com gateway, 3CRWE51196, to my isp. My problem is that the gateway does not provide me with a good dns.
In the web interface I added my isp's dns:es but my clients gets the gateways ip-address as dns, which does not answer to any dns requests.
The only workaround I have found so far is to set the dns on my clients manually. For the desktops it's no problem but I use my laptop in many different networks and it would be nice if a good dns was given together with the ip-address, i.e normal dhcp setup.
Firware on the gatway is V1.04.01 (isp requires PPTP for authentication)

Has anybody managed set up their 3CRWE51196 (or similar gateway) to provide dns?

 

[bdahl]

Greetings Shaglund,

Although I have no direct experience with this specific router, most routers of this type are fairly similar.

Often, our customers enter more information into the router than is required. We suggest that DNS info NOT be entered into the router (if possible - sometimes you need to enter 0.0.0.0), often the info will be picked up/assigned automatically.

Once again, this may not be the case with your router, but is definitely worth trying.

Best of luck,

Bdahl

 

[bcastner]

What is returned with by a client using DHCP? It should assign a client IP, a Gateway address of the router itself, and either the Router as DNS proxy server or the actual DNS entries of your ISP.

From your description it sounds as if DHCP is working, but the proxy server of the router is not.

Check your IE settings: Tools, Internet Options, Connections, LAN settings. Uncheck Autmatic Discovery, and uncheck any Proxy. There should be not settings checked on this page.

 

[shaglund]

The client gets ip-address (ofcourse), gateway which is gateways ip (192.168.1.1) and dns which also is gateways ip.

I figured out that the DNS forwarding in the gateway seems to be broken. It should forward any dns requests to the dns assigned when it connects to the isp but the gateway refuses to answer to any dns requests (no response on port 53)

 

[bcastner]

You positive there are no firewall issues involved here?

 

[shaglund]

The router has a builtin firewall, I've tried with both enabled and disabled firewall.

On the clients I use Windows XP, Windows 2000 Pro and Debian GNU/Linux, no firewalling software running on any of them. I even tried to telnet to port 53 on the router.

 

[bcastner]

Try a firmware reflash of the router/Gateway. Make certain to do it from a wired client, no other clients connected.

Do a full factory default setting reset first.
Reflash the firmware.
Do a reset again.
Unplug for 30 seconds.
Restore power and put your settings back in.