prefix-delegation

Function

The prefix-delegation command configures an agent prefix in the address pool view.

The undo prefix-delegation command deletes the agent prefix in the address pool view.

By default, no IPv6 address agent prefix is configured in the address pool view.

Format

prefix-delegation ipv6-prefix/ipv6-prefix-length assign-prefix-length [ life-time { valid-lifetime | infinite } { preferred-lifetime | infinite } ]

prefix-delegation ipv6-prefix/ipv6-prefix-length assign-prefix-length [ life-time preferred-lifetime days days [ hours hours [ minutes minutes [ seconds seconds ] ] ] valid-lifetime days days [ hours hours [ minutes minutes [ seconds seconds ] ] ] ]

prefix-delegation ipv6-prefix/ipv6-prefix-length lock

undo prefix-delegation ipv6-prefix/ipv6-prefix-length [ lock ]

Parameters

Parameter	Description	Value
ipv6-prefix/ipv6-prefix-length	Specifies the address prefix and the prefix length bound to an IPv6 address pool.	The value is a 32-digit hexadecimal number, in the format X:X::X:X/M. The IPv6 address prefix length ranges from 1 to 128.
assign-prefix-length	Specifies the default prefix length. NOTE: If the DHCPv6 server has been configured to allocate prefix lengths based on the DHCPv6 client requests, and the client-requested prefix length is within the range from ipv6-prefix-length to assign-prefix-length, the server allocates the prefix length based on the client request. If the client-requested prefix length is not within the preceding range or the server is not configured to allocate prefix lengths based on the DHCPv6 client requests, the server allocates the default prefix length. You can run the dhcpv6 server allow-hint or dhcpv6 server pool-name allow-hint command to configure the server to allocate prefix lengths based on the DHCPv6 client requests.	The value is an integer that ranges from 1 to 128. The assign-prefix-length must be greater than or equal to ipv6-prefix-length. The difference between the assign-prefix-length and ipv6-prefix-length must be less than or equal to 16.
life-time	Specifies the lifetime of the address prefix bound to an IPv6 address pool.	-
valid-lifetime	Specifies the valid lifetime.	The value ranges from 60 to 172799999, in seconds. The default value is 172800, that is two days.
preferred-lifetime	Specifies the preferred lifetime. The preferred lifetime cannot exceed the valid lifetime.	The value ranges from 60 to 172799999, in seconds. The default value is 86400, that is one day.
infinite	Sets the lifetime to infinite. When the preferred lifetime is set to infinite, the valid lifetime must be set to infinite.	-
preferred-lifetime days days [ hours hours [ minutes minutes [ seconds seconds ] ] ]	Specifies the preferred lifetime of the IPv6 prefix. The time must be no less than 1 minute.	days: indicates days. The value is an integer that ranges from 0 to 1999. hours: indicates hours. The value is an integer that ranges from 0 to 23. minutes: indicates minutes. The value is an integer that ranges from 0 to 59. seconds: indicates seconds. The value is an integer that ranges from 0 to 59.
valid-lifetime days days [ hours hours [ minutes minutes [ seconds seconds ] ] ]	Specifies the valid lifetime of the IPv6 prefix. The time must be no less than 1 minute and cannot be less than the preferred lifetime.	days: indicates days. The value is an integer that ranges from 0 to 1999. hours: indicates hours. The value is an integer that ranges from 0 to 23. minutes: indicates minutes. The value is an integer that ranges from 0 to 59. seconds: indicates seconds. The value is an integer that ranges from 0 to 59.
lock	Locks the address prefix.	-

Views

IPv6 address pool view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

When the device functions as a DHCPv6 PD server, run the prefix-delegation command to configure an agent prefix in the address pool view. The DHCPv6 PD client divides the obtained prefix into prefixes of subnet segments and sends an RA message on the network segment that hosts directly connect to or exchange information with hosts using the DHCPv6 protocol. The RA message contains the prefixes of subnet segments. This enables hosts to automatically configure addresses.

Precautions

Idle addresses or prefixes are assigned to DHCPv6 clients from the IPv6 address pool. Reserved addresses, conflicted addresses, and used addresses cannot be assigned to DHCPv6 clients. Reserved addresses include unspecified addresses, multicast addresses, loopback addresses, link-local addresses, NSAP addresses, and anycast addresses (defined in RFC 2526).
The agent prefix cannot be overlapped.
The agent prefix cannot be overlapped with the address prefix.
The agent prefix cannot be overlapped with the prefix statically specified by a certain user.
When the prefix pool is deleted, all prefix leases are deleted.
Only one agent prefix can be configured for an address pool.

Example

# Configure the agent prefix of the DHCPv6 server as fc00:1::/30 for the address pool pool1, set the prefix length to 42 and the lifetime to infinite.

<HUAWEI> system-view
[HUAWEI] dhcpv6 pool pool1 
[HUAWEI-dhcpv6-pool-pool1] prefix-delegation fc00:1::/30 42 life-time infinite infinite