回複：I had the same problem a few days ago

My situation is the opposite of yours. I have been using an old modem without any problem untill the day before yesterday. So I did what you said, replaced the old modem with the new one that ATT DSL sent me, now only one of the PCs has Internet connection. The second one couldn't even access any one of

192.168.1.1
192.168.0.1
192.168.0.0
192.168.1.0

I had no clue what went wrong.