You can access the 600 in AP mode if you can find out what the IP address its getting from the host router. I have my spare DGL-4500 set up in AP mode and it gets a specific address from my DIr-825. I can use the specified IP address to log into the 4500 while in AP mode.
Ok, if your wired all around then you should be ok for gaming. I would check out some CAT6 cabling as it's cheap now days. Be aware that some inbox cables that come with modems and routers are not the best sometimes.
seems like your using the 600 routers as a switch more than a AP. I will work too. However if your letting the DSL modem and router handle most of the traffic management, it might be best to use a network switch instead of a router made into an AP. There are still some processing that is uneccesary going on the 600 router. Also if you can get on the 600 web page, turn off it's firewall settings, QoS engine, wish and most everything that is not needed aside the IP address for the router and gateway. Other than those 2 times, it should work ok. For gaming though, I would recommend using a network switch instead of the AP router while your using the DSL modem has the host router.
Does the DSL modem router have a DMZ? If you find the IP address of the 600, put that in the DMZ on the DSL modem router and see how it goes.
It's too bad the DSL modem doesn't support bridging, usually they do. You would be good if you could bridge the modem and get yourself a DGL-4500 router.
