R21xx-HP FlexFabric 11900 Layer 3 IP Services Configuration Guide

152
4.
The DHCPv6 server sends a Reply message to the client, confirming that the address/prefix and
other configuration parameters are assigned to the client.
Figure 59 Assignment involving four messages
Address/prefix lease renewal
An IPv6 address/prefix assigned by a DHCPv6 server has a valid lifetime. After the valid lifetime expires,
the DHCPv6 client cannot use the IPv6 address/prefix. To use the IPv6 address/prefix, the DHCPv6 client
must renew the lease time.
Figure 60 Using the Renew message for address/prefix lease renewal
As shown in Figure 60, at T1, the DHCPv6 client sends a Renew message to the DHCPv6 server. The
recommended value of T1 is half the preferred lifetime. The DHCPv6 server responds with a Reply
message, informing the client about whether or not the lease is renewed.
Figure 61 Using the Rebind message for address/prefix lease renewal
As shown in Figure 61, if the DHCPv6 client receives no response from the DHCPv6 server after sending
a Renew message at T1, it multicasts a Rebind message to all DHCPv6 servers at T2 (when 80% preferred