Advanced Alerts

Do all the nodes have the same text in them that identifies them?  If so you would use

Node Name contains %xxxx%

The % is the equivalent of a wildcard for SQL.

You can use that in your advanced alerts; just know that this statement will alert when your nodes are unknown or warning as well - not just Down.

Trigger Alert when all of the following apply.

     Node Status is not equal to Up     -- if you want only DOWN nodes adjust to 'Node Status is Equal to DOWN'

     Node Name contains TEXT

If you want the reverse, where you want to alert on all the nodes that DO NOT have said 'TEXT' - create the alert then convert to SQL Alert.

  * Then Add in the

         Nodes.Name <> '%TEXT%'

(there is only a Node Name Does Not Equal - not a 'Does Not Contain'  (at least through 11.0)