SQL server won't start on 2nd node (No such host is known)

Hello,

We have a 2 node SQL 2008 cluster.
But failover is failing, because one of the nodes throws an error when it should start.
When I manualy failover to test the cluster this error is thrown:

The SQL Server (MSSQL) service terminated with the following error:
No such host is known.

This error is shown in the eventviewer.
When this error occurs, the SQL service returns to its previous owner.

Google didn't help me on this error, especialy the "no such host is known" is unknown on google.