HP Serviceguard manual Preceding two bullets, Default is, When a network interface card has failed

first determine the Maximum Bridge Transit Delay (MBTD) for each switch and router. The value should be in the vendors' documentation. Set the CONFIGURED_IO_TIMEOUT_EXTENSION to the sum of the values for the switches and routers. If there is more than one possible path between the NFS server and the cluster nodes, sum the values for each path and use the largest number.

CAUTION: Serviceguard supports NFS-mounted file systems only over switches and routers that support MBTD. If you are using NFS-mounted file systems, you must set CONFIGURED_IO_TIMEOUT_EXTENSION as described here.

For a fuller discussion of MBTD, see the white paper Support for NFS as a file system type with Serviceguard 11.20 on HP-UX 11i v3 which you can find at http:// www.hp.com/go/hpux-serviceguard-docs.

• For clusters in which both of the above conditions

	apply.
	In this case, set the
	CONFIGURED_IO_TIMEOUT_EXTENSION to the higher
	of the two values you get from following the instructions
	in the preceding two bullets.
	Default is 0.
NETWORK_FAILURE_DETECTION	The configuration file specifies one of two ways to decide
	when a network interface card has failed:
	• INOUT
	• INONLY_OR_INOUT
	The default is INOUT.
	See “Monitoring LAN Interfaces and Detecting Failure: Link
	Level” (page 69) for more information.
	Can be changed while the cluster is running.
NETWORK_AUTO_FAILBACK	How Serviceguard will handle the recovery of the primary
	LAN interface after it has failed over to the standby interface
	because of a link level failure. Valid values are YES and
	NO. YES means the IP address(es) will fail back to the
	primary LAN interface from the standby when the primary
	LAN interface recovers at the link level. NO means the IP
	address(es) will fail back to the primary LAN interface only
	when you use cmmodnet (1m) to re-enable the interface.
	Default is YES.
SUBNET	IP address of a cluster subnet for which IP Monitoring can
	be turned on or off (see IP_MONITOR). The subnet must be
	configured into the cluster, via NETWORK_INTERFACE and
	either HEARTBEAT_IP or STATIONARY_IP. All entries for
	IP_MONITOR and POLLING_TARGET apply to this subnet
	until the next SUBNET entry; SUBNET must be the first of
	each trio.

122 Planning and Documenting an HA Cluster