You can configure the dead interval to specify how long hello packets will not be received by the router before neighbors declare that the router is down. This value must be a multiple of the hello interval value, and must be the same for all routers attached to the same link.
This example sets the dead interval for VLAN 10 to 120 seconds.
SEFOS(config)# interface vlan 10 SEFOS(config-if)# ipv6 ospf dead-interval 120 SEFOS(config-if)# end
SEFOS# show ipv6 ospf interface vlan 10 Ospfv3 Interface Information Interface Name: vlan10 Interface Id: 41 Area Id: 0.0.0.6 Local Address: fe80::214:4fff:fe6c:628f Router Id: 10.0.0.1 Network Type: BROADCAST Cost: 1 State: BACKUP Designated Router Id: 10.0.0.8 local address: fe80::214:4fff:fe6c:d04d Backup Designated Router Id: 10.0.0.1 local address: fe80::214:4fff:fe6c:628f Transmit Delay: 1 sec Priority: 1 IfOptions: 0x0 Timer intervals configured: Hello: 10, Dead: 120, Retransmit: 5, Poll: 120 Demand Circuit: Disable Neighbor Probing: Disable Nbr Probe Retrans Limit: 10 Nbr Probe Interval: 120 Hello due in 4 sec Neighbor Count is: 1 Adjacent with neighbor 10.0.0.8