Ubuntu Server and Internet-Connection drops

hi,

i have the following problem with ubuntu server 10.04:

from time to time the server drops the connection to the internet. i can ping and connect to others in the local network, but i can't ping external domains or make an apt update. the dns entries in resolv.conf are the right ones. another crazy thing is, if internet works and i start calendarserver (have removed it right now), the internet connection drops as well. when i restart it works again!

any advice? maybe some dns issue?

thanks in advance!

From serverfault Tronic

• Very vague question.

  In the absence of any sensible diagnostics I'd bet on it being nothing to do with the Ubuntu box - but rather a problem with the machinery connecting you to the internet.

  How do you connect? If its via ADSL / SDSL then its probably your carrier dropping the connection. Is there a router between the ubuntu box and the wires? A Modem? What does it report when the connection is down?

  From symcbean

• nslookup www.google.com. save one of the ips and when the internet is dead, try to ping the ip. if it works, then it's a dns problem. if it doesn't then it would a routing issue.

  From Nikolaidis Fotis