F5 Newbie - Just Starting

Check your server routing. Do the ping and "telnet " as suggested in the previous post, and if one or both fail, you probably have an additional NIC on the server with a different gateway (i.e. requests are going in one interface and out another). Otherwise, it is an ACL on the server not allowing the BIG-IP interface, or the standard "GET /" send string in the built-in monitor is getting kicked back. This usually means you need to create your own monitor, use http as the parent monitor, and put something more meaningful in the send and/or receive string field. Finally, you may just have the wrong server port. If you added the node without a port, it will default to the wildcard zero (*any port), in which case any service monitor will fail.