HP Serviceguard manual See Monitoring LAN Interfaces and Detecting Failure IP

	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 73) 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.
POLLING_TARGET	The IP address to which polling messages will be sent from
	all network interfaces on the subnet specified in the
	preceding SUBNET entry, if IP_MONITOR is set to ON. This
	is called target polling.
	Each subnet can have multiple polling targets; repeat
	POLLING_TARGET entries as needed.
	If IP_MONITOR is set to ON, but no POLLING_TARGET is
	specified, polling messages are sent between network
	interfaces on the same subnet (peer polling). HP recommends
	you use target polling; see “How the IP Monitor Works”
	(page 74) for more information.

Cluster Configuration Planning 123