Specifies the time in milliseconds for which the router is considered to be reachable.
The default value of "0" means that the router advertisements have no specifications for reachable time.
- SNMP ID:
 - 2.70.2.2.8
 - Console path:
 - Setup > IPv6 > Router-Advertisement > Interface-Options
 - Possible values:
 0 … 2147483647 Milliseconds
- Default:
 - 0