Martin "Conzi" Conzelmann had the great idea to monitor the Equallogic's for ethernet packet errors - something very important to monitor on ISCSI SAN's! He contributed the new check type "etherrors" to the check_equallogic plugin. It has already proven its function as one of his own Equallogics is currently having ethernet packet errors...
The new check type is now available (version 20110328). This is a BETA release of the check type so I'd be happy to hear as much feedback as possible.