H3C Technologies H3C S5560 Series Switches - Manual (Page 187)

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PD
The DHCPv6 server creates a prefix delegation (PD) for each assigned prefix to record the following
details:
• IPv6 prefix.
• Client DUID.
• IAID.
• Valid lifetime.
• Preferred lifetime.
• Lease expiration time.
• IPv6 address of the requesting client.
DHCPv6 address pool
The DHCP server selects IPv6 addresses, IPv6 prefixes, and other parameters from an address pool, and
assigns them to the DHCP clients.
Address allocation mechanisms
DHCPv6 supports the following address allocation mechanisms:
• Static address allocation—To implement static address allocation for a client, create a DHCPv6
address pool, and manually bind the DUID and IAID of the client to an IPv6 address in the DHCPv6
address pool. When the client requests an IPv6 address, the DHCPv6 server assigns the IPv6
address in the static binding to the client.
• Dynamic address allocation—To implement dynamic address allocation for clients, create a
DHCPv6 address pool, specify a subnet for the pool, and divide the subnet into temporary and
non-temporary IPv6 address ranges. Upon receiving a DHCP request, the DHCPv6 server selects an
IPv6 address from the temporary or non-temporary IPv6 address range based on the address type
in the client request.
Prefix allocation mechanisms
DHCPv6 supports the following prefix allocation mechanisms:
• Static prefix allocation—To implement static prefix allocation for a client, create a DHCPv6 address
pool, and manually bind the DUID and IAID of the client to an IPv6 prefix in the DHCPv6 address
pool. When the client requests an IPv6 prefix, the DHCPv6 server assigns the IPv6 prefix in the static
binding to the client.
• Dynamic prefix allocation—To implement dynamic prefix allocation for clients, create a DHCPv6
address pool and a prefix pool, specify a subnet for the address pool, and apply the prefix pool to
the address pool. Upon receiving a DHCP request, the DHCPv6 server dynamically selects an IPv6
prefix from the prefix pool in the address pool.
Address pool selection
The DHCPv6 server observes the following principles when selecting an IPv6 address or prefix for a
client:
1. If there is an address pool where an IPv6 address is statically bound to the DUID or IAID of the
client, the DHCPv6 server selects this address pool. It assigns the statically bound IPv6 address or
prefix and other configuration parameters to the client.