I don't think the beta is suitable for 841N, it seems every model has difference firmware

leave it as 0, it means the DMZ is disabled

larryb wrote I just installed this modem/router last night and am having the same problem. Anyone get a resolution? the same on different web browser and different device? how about a factory reset?

clear cookies and history? since ip works, it is ok for me that domain name didn't work.

no, 32 is the limit. but you email tp-link support as suggestion to support more then 32 devices under dhcp reservation

I think you can try the reset after you make a back up, since it's been working for some time. If no fix, contact tplink support again.