In IPv6, the T1 renewal timer triggers the first renewal attempt at what percentage of the lease duration?

• A. 25%
• B. 50%
• C. 75%
• D. 90%

Answer: (B)

In IPv6, a DHCPv6 client renews its address lease using two timers, and the first renewal attempt happens at half of the lease duration. This T1 value is set to 50% of the lease, giving the client time to contact the DHCPv6 server and renew before the lease expires. If that renewal doesn’t succeed, the client will try again later at T2 with any available server. So the first renewal is triggered when 50% of the lease time has elapsed.