DNS client error?
Between 2 and 3 p.m. on Monday, my Xandros box stopped being able to browse the net. It still works as a server (web, imap, ftp), but it cannot resolve domain names, so I can't browse the web, and it can't send mail via smtp. I know it was between 2 and 3 because I have set fetchyahoo to run every hour; at 2 it worked, at 3 it failed because it couldn't resolve mail.yahoo.com. But I have no idea why.
I have looked all over for information on dns clients, which I presume is the problem, but I haven't found an answer. Dhcp is still working, at least to the extent that it can get an ip address. Why it can't get to a dns and resolve names is a mystery.
Please give me a hint! I am happy to read up on this, but almost everything dns-related for Linux is about setting up a server.
Check the condition of your link to the internet. Is it broken? Can you establish that you are logged in and connected to your ISP? Pinging a known IP address would do.
Then check the servers list in /etc/resolv.conf. Are the servers still in operation? Run nslookup - it should say it is using the first server in the list. Enter something like www.google.com. (note the end ".") Does it work? If not, you need to change the server list to servers that are alive and well.