When I try to access Google, (and some other sites) I get the message "Firefox can't establish a connection to the server at 255.255.255.255." and the address in the title bar is "http://255.255.255.255" This problem just started today.

Same problem here. Happens w/ Firefox and IE. Two Thinkpads wirelessly connected to Linksys WRT54GL. Other sites besides Google seem fine. Clearing DNS cache didn't help.

Changing my DNS server from automatic to 4.2.2.6 w/ 4.2.2.4 as backup fixed my problem. I have RCN high speed internet. Are you on RCN, Mongusa? Here's how to change DNS servers for Win XP. http://www.dslreports.com/faq/8164 Probably something similar for Vista. Good luck.

Yes I am on RCN high speed internet. DNS servers were set to automatic. I entered the numbers above and lost all internet connection. When restablished connection problem remained. Maybe I am misunderstanding the addresses written above?

OK, good to know that this is probably a problem at RCN--not at home, eg, malware. Here's another link for changing DNS servers. http://www.mediacollege.com/compute... 4.2.2.6 and 4.2.2.4 are common alternatives to ISP DNS servers. Just type those numbers in for the preferred and alternate DNS servers.

When I entered the numbers above I lost all connection to the internet. When I restablished connection problem remained. However when I logged on this morning, the problem disappeared. I guess it was a problem with RCN. (grrr!.) (I actually lose connection with RCN 3 or 4 times a day for no reason, connection resumes after about 15 minutes to 1/2 hour. Now this. I used to really like their service.) Anyway, thanks for responding so promptly and for all your help. It is greatly appreciated.