System Administration Guide: IP Services

Preventing Applications From Using Test Addresses

After you have configured a test address, you need to ensure that this address is not used by normal applications. If you let applications use the test address, applications fail, because test addresses do not fail over during the failover operation. To ensure that IP does not pick the test address for normal applications, you mark the test address deprecated by using the ifconfig command. This parameter has the following syntax:

ifconfig interface-name deprecated

After you mark the address as deprecated, IP does not pick this address as a source address for any communication, unless the applications explicitly bind to the address. Only in.mpathd explicitly binds to such an address. See How to Configure a Multipathing Interface Group With Two Interfaces.

Because link-local addresses are not present in the name service (DNS, NIS, and NIS+), applications do not use link-local addresses for communication. Consequently, you do not need to mark IPv6 test addresses as deprecated.

Note –

You must not mark IPv6 link-local addresses as deprecated.

Use the -deprecated option to turn off the deprecated attribute of the address.

Note –

IPv4 test addresses should not be placed in the name service tables (DNS/NIS/NIS+). In IPv6, link-local addresses are used as test addresses and are not normally placed in the name service tables.

Autoconfigured IPv6 addresses are not preserved across system reboot. If you require that IP addresses be preserved across reboot, then applications should use static IP addresses.