I have DSL and a Linksys WRT54G router. I was living at my friend's house and we were using this router. In almost every way it works fine. The problem I had was that many times when logging into WOW I would log in disconnected. Ping would be 0. All the other characters would either be invisible or running in place or not moving at all. I would not be able to logout or exit through the menu, it just wouldn't respond to that. Eventually it would log me out. Otherwise I would have to hit Alt+F4. All of this happened with my roommate's computers as well.
It was always really bad after a new patch. We tried to disable all addons and delete the addons folder and/or reinstall WOW, but that didn't help.
I just moved to an apartment with DSL and I'm using the same Linksys router. The problems continued. The friend that I lived with said that since he went back to his old 16 port hub he's had no issues at all. Last night I was having lots of trouble after the newest patch. So I bypassed the router and plugged directly into the modem, and I was able to connect immediately. I had no other problems the rest of the night.
The router works fine otherwise. I have two computers wired to it. My new roommates use their laptops on it wirelessly. The PS3 is wired to it and works fine, and the Wii is connected through wireless and works fine.
So the TL;DR of it is, WOW doesn't work properly on my linksys, but there doesn't seem to be anything wrong with it. Has anyone had this problem or is there anything I can do at the linksys config page to fix this? I'll probably call Linksys about this too, and email Warcraft support, but I figured while I'm at work I'll see what any of you think. Thanks in advance.
But, if you are after mere parlor tricks, you will be sorely disappointed. For if I reach behind your ear, it will not be a nickel I pull out, but your very soul!