appliance has one built-in monitor that can be used to monitor NNTP services:
NNTP monitor. It periodically checks the NNTP
service to which it is bound by connecting to the service and checking for the
existence of the newsgroup that you specify. If the newsgroup exists, the
search is successful and the service is marked UP. If the NNTP service does not
respond or the search fails, the service is marked DOWN.
Note: Monitor probes originate from the NetScaler IP (NSIP) address.
The NNTP monitor can
optionally be configured to post a test message to the newsgroup as well.