Related Documentation
Configuring DHCPv6 Prefix Exclude Option
You can use Dynamic Host Configuration Protocol version 6 (DHCPv6) prefix delegation to automate the delegation of IPv6 prefixes to the CPE. With prefix delegation, a delegating router - the broadband network gateway (BNG) delegates IPv6 prefixes to a requesting router, the customer premises equipment (CPE). Junos OS allows the exclusion of one specific prefix from a delegated prefix set while using DHCPv6 based prefix delegation as described in RFC 6603. This excluded prefix is used as the link between the delegating router and the requesting router. This prefix link is intended for use in networks where each requesting router is in its own layer 2 domain. If the DHCP server supporting exclude prefix wants client to request for prefix exclude after reconfiguration, then you can configure PD_Exclude in the reconfigure message.
Before you begin, configure the device interfaces.
To configure DHCPv6 prefix exclude:
- Configure the prefix length to be excluded from a delegated
prefix set pool. This prefix is used as the link between the delegating
router and the requesting router. The exclude prefix length is bigger
than the given prefix length.[edit access address-assignement pool pool-name family inet6 dhcp-attributes]user@host# set exclude-prefix-len prefix-length
For example, for prefix delegated in 2001:db8::/32 , configure the exclude prefix as 2001:db8:ffff:fffc::/72 for delegated pool prefix_delegate_pool.
[edit access address-assignment pool prefix_delegate_pool family inet6 dhcp-attributes]user@host# set exclude-prefix-len 72 - Configure PD_Exclude option support in the reconfigure
message. In case the server wants the client to request for the prefix
to be excluded after reconfiguration then the exclude prefix options
is added in Option Request option (ORO) in reconfigure message.[edit system services dhcp-local-server dhcpv6 reconfigure]user@host# set support-option-pd-exclude
- Configure PD_Exclude option support in the reconfigure
message for a given group.[edit system services dhcp-local-server dhcpv6 group group-name reconfigure]user@host# set support-option-pd-exclude
