Address/Prefix Lease Renewal - HP 5920 Series Configuration Manual

Figure 57 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 58 Using the Renew message for address/prefix lease renewal
As shown in Figure 58, 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 59 Using the Rebind message for address/prefix lease renewal
As shown in Figure 59, 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
lifetime elapses). The DHCPv6 server responds with a Reply message, informing the client about whether
or not the lease is renewed.
If the DHCPv6 client receives no response from any DHCPv6 server before the valid lifetime expires, the
client stops using the address/prefix.
For more information about the valid lifetime and the preferred lifetime, see "Configuring basic IPv6
settings."
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