2.70.2.2.11 Def.-Lifetime

Specifies the time in seconds for which the router is considered to be reachable in the network.

Note: If this value is set to 0, the operating system will not use this router as the default router.
Telnet path:
Setup > IPv6 > Router-Advertisements > Interface-Options > Def.-Lifetime
Possible values:
Max. 10 numbers in the range 0 – 2147483647
Default:
1800