World Community Grid - View Thread - BOINC: ... can't / couldn't resolve hostname

Out of the blue, this often happens when somewhere on the planet, starting at the host's location the DNS was broken. A typical series of messages to appear in the BOINC log are:

13/06/2009 08:52:10 WCG Started upload of CMD2_0008-MYH2A.clustersOccur-MYH3.clustersOccur_320_1_0
13/06/2009 08:52:10 WCG Sending scheduler request: To fetch work.
13/06/2009 08:52:10 WCG Requesting new tasks
13/06/2009 08:52:26 BOINC can't access Internet - check network connection or proxy configuration. (1)
13/06/2009 08:52:26 WCG Temporarily failed upload of CMD2_0008-MYH2A.clustersOccur-MYH3.clustersOccur_320_1_0: can't resolve hostname
13/06/2009 08:52:26 WCG Backing off 1 min 0 sec on upload of CMD2_0008-MYH2A.clustersOccur-MYH3.clustersOccur_320_1_0
13/06/2009 08:52:26 WCG Scheduler request failed: Couldn't resolve host name
13/06/2009 08:53:10 WCG Started upload of CMD2_0008-MYH2A.clustersOccur-MYH3.clustersOccur_320_1_0
13/06/2009 08:53:14 WCG Temporarily failed upload of CMD2_0008-MYH2A.clustersOccur-MYH3.clustersOccur_320_1_0: can't resolve hostname
13/06/2009 08:53:14 WCG Backing off 1 min 0 sec on upload of CMD2_0008-MYH2A.clustersOccur-MYH3.clustersOccur_320_1_0
13/06/2009 08:58:09 WCG Started upload of CMD2_0008-MYH2A.clustersOccur-MYH3.clustersOccur_320_1_0
13/06/2009 08:58:10 WCG Sending scheduler request: To fetch work.
13/06/2009 08:58:10 WCG Requesting new tasks

Do the following one by one and see at each step if the problem no longer shows:

First boot your modem and/or router to refresh the IP pathways to include those to your ISP,

Fully stop and start BOINC including the service,

Boot the computer(s) that has/have the problem.

After adding the 2 WCG IP addresses to the 'hosts' file, see FAQ , this issue may be permanently resolved.

There could though be a real proxy issue per the first bold line in above boxed message log marked (1). Then visit Help: http://www.worldcommunitygrid.org/help/viewTopic.do?shortName=proxy

Further cases are discussed in this external wiki Can't resolve hostname '(host-name)' host not found

Of course there's the possibility that the servers are really down. See FAQ When Client-Server Communications Started to be Troublesome for more information