ipv6 dhcp server forbidden-prefix
Use ipv6 dhcp server forbidden-prefix to exclude IPv6 prefixes in the DHCPv6 prefix pool 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 ] [ vpn-instance vpn-instance-name ]
undo ipv6 dhcp server forbidden-prefix start-prefix/prefix-len [ end-prefix/prefix-len ] [ vpn-instance vpn-instance-name ]
Default
No IPv6 prefixes in the DHCPv6 prefix pool are excluded from dynamic allocation.
Views
System view
Predefined user roles
network-admin
mdc-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 in the range of 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.
vpn-instance vpn-instance-name: Specifies an MPLS L3VPN instance by its name, a case-sensitive string of 1 to 31 characters. If the excluded IPv6 prefixes belong to the public network, do not specify this option.
Usage guidelines
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.
You can execute this command multiple times to exclude multiple IPv6 prefix ranges from dynamic allocation.
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