ipv6 dhcp server forbidden-prefix

Use ipv6 dhcp server forbidden-prefix to exclude specific IPv6 prefixes from dynamic allocation.

Use undo ipv6 dhcp server forbidden-prefix to remove the configuration.

Syntax

ipv6 dhcp server forbidden-prefix start-prefix/prefix-len [ end-prefix/prefix-len ]

undo ipv6 dhcp server forbidden-prefix start-prefix/prefix-len [ end-prefix/prefix-len ]

Default

No IPv6 prefixes in the DHCPv6 prefix pool are excluded from dynamic allocation.

Views

System view

Predefined user roles

network-admin

Parameters

start-prefix/prefix-len: Specifies the start IPv6 prefix. The prefix-len argument specifies the prefix length in the range of 1 to 128.

end-prefix/prefix-len: Specifies the end IPv6 prefix. The prefix-len argument specifies the prefix length, ranging from 1 to 128. The value for end-prefix cannot be lower than that for start-prefix. If you do not specify this argument, only the start-prefix/prefix-len is excluded from dynamic allocation. If you specify this argument, the prefixes from start-prefix/prefix-len to end-prefix/prefix-len are all excluded.

Usage guidelines

You can exclude multiple IPv6 prefix ranges from dynamic allocation.

If the excluded IPv6 prefix is in a static binding, the prefix can still be assigned to the client.

The prefix or prefix range specified in the undo form of the command must be the same as the prefix or prefix range specified in the command. To remove a prefix that has been specified as part of a prefix range, you must remove the entire prefix range.

Examples

# Exclude IPv6 prefixes from 2001:3e11::/32 through 2001:3eff::/32 from dynamic allocation.

<Sysname> system-view
[Sysname] ipv6 dhcp server forbidden-prefix 2001:3e11::/32 2001:3eff::/32

Related commands

• ipv6 dhcp server forbidden-address

• static-bind