Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide - Manual (Page 212)

DHCPv6 Relay Agent Prefix Delegation Notification
DHCPv6 Relay Agent Prefix Delegation Notification feature allows a DHCPv6 server to dynamically
delegate IPv6 prefixes to a DHCPv6 client using the DHCPv6 Prefix Delegation (PD) option. DHCPv6
prefix delegation enables an Internet service provider (ISP) to automate the process of assigning
prefixes to a customer premises equipment (CPE) network. The CPE then assigns IPv6 subnets from
the delegated IPv6 prefix to its downstream customer interfaces.
This feature description is shown in Figure 18 .
FIGURE 18 DHCPv6 Relay Agent Prefix Delegation Notification
A route is added to the IPv6 route table on the provider edge router (PE) for the delegated prefix to be
delegated to requesting routers. The delegating router chooses a prefix for delegation and responds
with it to the requesting router. to the external network and to enable the correct forwarding of the IPv6
packets for the delegated IPv6 prefix. Adding the delegated prefix to the IPv6 route table ensures that
the unicast Reverse Path Forwarding (uRPF) works correctly.
Since the PE is also a DHCPv6 relay agent (it relays DHCPv6 messages between the CPE and the
DHCP server), it examines all DHCPv6 messages relayed between the CPE and the DHCP server
and gathers information about a delegated prefix and then manages the advertisement of this
delegated prefix to the external network.
DHCPv6 Relay Agent Prefix Delegation Notification limitations
The following limitations apply to the DHCPv6 Relay Agent Prefix Delegation Notification.
DHCPv6 Relay Agent Prefix Delegation Notification
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