Debian Configuration :: Ssh Cannot Resolve Nodename After Wakeonlan

Previously, I issued a wakeonlan command to my sleeping debian (wheezy stable) server from (a mac) within my home network and then ssh in no problem. Worked like a charm. I could put it to sleep again and wake it up etc. Perfecto.

However, for some reasonI can now only ssh in once the server is rebooted (by physically switching it off then on again). If I put it to sleep then wake it, it does wake up --- however, ssh cannot then resolve the hostname:

---
>> ssh -vX bob@cerberus.local
OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011
debug1: Reading configuration data /Users/bob/.ssh/config
debug1: Reading configuration data /etc/ssh_config
debug1: /etc/ssh_config line 20: Applying options for *
debug1: /etc/ssh_config line 102: Applying options for *
ssh: Could not resolve hostname cerberus.local: nodename nor servname
provided, or not known