Hey GZers.

Ok so i've moved to a new place and which has Telecom dsl. They are using the supplied ST modem which is working fine. They also have a belkin router, which is not so good. So i've bought a nice shiny Asus router and put DD-WRT v24 on it and its all set up fine and dandy.

Now, to avoid double NAT and make things a little nicer and faster I want to half-bridge the modem to the router.

On the ST it gives you the option to assign the public IP to a device. Great. When I do that to the belkin router it works fine. Belkin picks up the WAN IP and gateway/dns etc and works a treat (within the belkins limitations of not being an overly good router). As a bonus it also seems to keep a route to the modem so i dont have to fiddle around changing IP addresses if i need to access the modem. Yee har!

However, switch it for the DD-WRT (and reassign the WAN IP to it in the ST) and houston we have a problem. It picks up the addresses fine via DHCP, shows the same address details as in the beklin, but it wont route anything to the WAN, and also wont route to the ST anymore. If i run a traceroute it just seems to loop in the router a couple of times then end.

If i use it without half bridging it works fine, but obviously that means double NAT.

Yes I have the modems/routers on different subnets (have the modem at 192.168.1.0/24 and the router on 192.168.3.0/24.

The only thing I can see which might put a stick in the works is that the upstream Telecom router is in 125.237.255.0/24 but my IP is in 222.154.182.0/24 - how that works is beyong my network skill but anyhoo that seems to be the deal.

So my guess is that DD-WRT maybe can't hack its WAN interface and gateway being on a different subnet? Yet the belkin can?

I might try a linksys AM300 instead, because this guy had more luck with it. Pity I just sent the one I had up to my dad last week.

Otherwise, any suggestions?