First post here so I'll start by saying "Hi".

I've just bought a 2820n to replace our existing ZyXel 660H.

I plug the 2820 into the DSL line and the DSL light comes up after training. I connect PCs directly to to the router and via wireless and everything works as it should.

Most of the 'stuff' on our LAN is connected to a Netgear GS116 switch. As soon as I plug that into the router I lose DSL sync. If I unplug everything from the switch so only it is connected to the router the same thing happens. I tried connecting via all the ports on the switch and all the ports on the router; no difference.

The same switch connected to the ZyXel and a back-up Belkin work as they should.

I then took the switch off the LAN and replaced it with a couple of 8-port Netgear switches. As soon as I plugged them into the router DSL went down. Again, these work perfectly with the ZyXel and Belkin.

I upgraded the firmware from the delivered 3.3.3 to 3.3.4 but it made no difference at all.

I'm wondering whether I need a crossover cable to connect the switch with but I'll be surprised if that is the case as the comparatively much cheaper ZyXel and Belkin routers seem to cope with it. Even if that is the issue, I don't understand why that should cause a problem with the DSL sync.

I also wonder if the Draytek router is faulty but why that should only manifest itself when I plug in a switch is equally baffling.

I'm at a loss.

Any ideas please?

Thanks.

Kevin

Did you try to upgrade the firmware on the Netgear box?

Yes, I updated it from 3.3.3 to 3.3.4 but it has made no difference.

I've just tried the RST file at the suggestion of Draytek support then set up Internet access and DHCP. Plugged the switch in on its own and DSL stayed up.

I then plugged a PC in to the switch and it went down again. I turned everything off then back on again. The router didn't seem to be able to get DSL sync with the switch and PC plugged in. Almost immediately after I unplugged the switch the DSL light went solid. I plugged the switch back in and it remained solid but kept going down and then coming back up again. I left it for a while to see if things would improve but it didn't.

I went back to the ZyXel on which DSL was also unstable for a while but then settled. I noticed this in my previous testing - after using the Draytek any router I tried would have a period of DSL sync. instability but would then settle.

Something I didn't mention before as it didn't seem relevant but I now think it may be. We've been using our ZyXel router for a long time and, while speeds have been low (~500kbps) as it's a stretch to the exchange, it has been reasonably stable. When I first put the Draytek on the line it was unable to get DSL sync. The problem persisted after I swapped back to the ZyXel and it was over 24 hours before I was able to get reconnected. I thought it was one of life's odd coincidences but now I'm not so sure.

Kevin