Hi,
I’m hoping this is just a configuration issue but after trying countless different combinations of settings and reading the FAQs I still cannot make this work.

I’ve a 2820n on BT business broadband which is my WAN1, and a separate connection and router which is connected as WAN2.

Both these connections run fine providing my test computer is assign a private IP by the router and don’t use any redirecting services such as DMZ Host, or Address Mapping.

If I assign my test machine one of my static IPs on WAN1 (which works fine), then the computer loses its connection when I pull the phoneline out and the router jumps to WAN2; it cannot resolve names, nor can it ping any IPs on the net.
The same thing occurs when I set the computer back to a privately assign IP and use DMZ host to forward data from the same static IP, it works fine on WAN1 but when the router jumps over to WAN2 the computer can’t see the net at all.
If I use Address Mapping to connect the static and private IPs again the same thing happens.

Obviously I don’t expect any ports to still be forwarded to the computer, but it should still have basic net access via WAN2?

I can post my configuration details if that would help.
Cheers in advance

You using ISP DNS servers? Maybe try something like OpenDNS as this is not locked to an ISP. Its free to use. Google OpenDNS & then test with a familiar site like bbc.co.uk or suchlike.

Unfortunately when using either opendns or google the same occurs.

Have you got an internal server looking at any DNS?

Have you got an internal server looking at any DNS?

No, not at the moment, I'm only testing the router so only have a single machine attached.

This is my current config, hopefully i've just set something incorrectly:


IP here is set to dynamic (because BT is weird), but if I go with just one IP statically set the same problem still occurs:


Sending the extra IPs to the NAT pool doesn't make a difference:


WAN2 is just being feed a static IP from another router:


As said above I've tried forcing a external DNS server as well:


Can anyone see anything obvious that's wrong?

Looks ok to me - unless someone else can see anything?

Have you tried a straight ping & tracert when things are going loopy to see where things are falling over.

I know BT mutliple IP addressing is odd. You get a dynamic address & then the statics appear beneath it somewhere.