How did you try doing that? In any event you should ensure the network is quick enough and the cluster is not experiencing any issues. You can enable logging (http://docs.couchbase.com/developer/c-2.4/logging.html and see what happens.
It might also be that you have a firewall blocking your connection, or one of the hosts is unreachable, etc. etc. – are you getting this error during initial connection? or just when you try to do operations?