I bought a DrayTek Vigor 100 ADSL2+ modem to use with my old 3Com 3CRWE754G72-A ADSL Wireless Router. Plugging in a laptop, the Vigor was easy to configure and I could access the Internet by configuring the Local Area Connection > TCP/IP properties with the standard Be fixed IP details.

I then setup the 3Com with Internet settings in 1483 Bridge mode, same fixed IP address, subnet mask 255.255.248.0, default gateway 94.193.104.1, VPI/VCI 0/101 and encapsulation LLC with DNS 87.194.0.66 and 67.

From my desktop PC I can see the Vigor via the router, and it says it is connected OK, but I cannot access the Internet.

Am I missing something obvious? I assume that an old ADSL router should work OK.

you may have to set the 3com to pppoe.

see here:
http://www.draytek.co.uk/support/kb_vigor100_setup.html

Thanks for the suggestion but no, 1483 Bridge Mode as stated.

i'm not aware that you can use it that way. the vigor 100/110 is a pppoe to pppoa bridge.
i have numerous v100's and they are all set this way.
see here:
http://www.draytek.co.uk/products/vigor110.html

That router is an ADSL router.
Presumably you have connected the modem to one of the LAN ports?

That isn't going to work, you need an ethernet router (cable router) and connect the modem into the WAN port.

Your router will only route between it's LAN and WAN. Between the LAN ports is just a network switch. Since this routers WAN port is ADSL there is no way to connect the modem to it.

Yes I had used a LAN port. I hadn't appreciated the significance of WAN ports on some routers having only ever set up LANs before.

In my defence I did wonder how the modem was going to get the WAN settings from the router.

My mum always told me not to mess with things I didn't understand :oops: