The in.mpathd multipathing daemon requires a test IP address for detecting failures and repairs. You must use a routeable address for this IP address. That is, the subnet prefix of the address must be known to any routers present on the link. You use the ifconfig command's new -failover option to configure a test address. Use the following syntax to configure a test address:
# ifconfig interface-name addif ip-address <other-parameters> -failover up
For <other-parameters>, use the parameters that are required by your configuration. See the ifconfig(1M) man page for descriptions. How to Configure a Multipathing Interface Group With Two Interfaces shows the steps you perform for an IPv4 test address.
For example, to add a new logical interface with an address of 126.96.36.199, the netmask and broadcast address set to the default value, and also configure the interface with a test address, type the following:
# ifconfig hme0 addif 188.8.131.52 netmask + broadcast + -failover up
You must mark an IPv4 test address as deprecated to prevent applications from using the test address. See How to Configure a Multipathing Interface Group With Two Interfaces.
Use failover without the dash to turn on the failover attribute of the address.
All test IP addresses in a multipathing group must use the same network prefix. That is, the test IP addresses must belong to a single IP subnet.