Managing Serviceguard Sixteenth Edition, March 2009

By default, each of the cluster subnets is listed
under SUBNET, and, if at least one gateway is
detected for that subnet, IP_MONITOR is set to
ON and POLLING_TARGET entries are populated
with the gateway addresses, enabling target
polling; otherwise the subnet is listed with
IP_MONITOR set to OFF.
See “Monitoring LAN Interfaces and Detecting
Failure: IP Level” (page 99) for more information.
Can be changed while the cluster is running;
must be removed, with its accompanying
IP_MONITOR and POLLING_TARGET entries,
if the subnet in question is removed from the
cluster configuration.
IP_MONITOR Specifies whether or not the subnet specified in
the preceding SUBNET entry will be monitored
at the IP layer.
To enable IP monitoring for the subnet, set
IP_MONITOR to ON; to disable it, set it to OFF.
By default IP_MONITOR is set to ON if a gateway
is detected for the SUBNET in question, and
POLLING_TARGET entries are populated with
the gateway addresses, enabling target polling.
See the POLLING_TARGET description that
follows for more information.
HP recommends you use target polling because
it enables monitoring beyond the first level of
switches, but if you want to use peer polling
instead, set IP_MONITOR to ON for this SUBNET,
but do not use POLLING_TARGET (comment
out or delete any POLLING_TARGET entries that
are already there).
If a network interface in this subnet fails at the
IP level and IP_MONITOR is set toON, the
interface will be marked down. If it is set to OFF,
failures that occur only at the IP-level will not be
detected.
Can be changed while the cluster is running;
must be removed if the preceding SUBNET entry
is removed.
156 Planning and Documenting an HA Cluster