© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Advanced IPv6 Topics Understanding DHCPv6 Prefix Delegation

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v DHCPv6 Prefix Delegation Stage 1: CPE initiates a connection to delegating router Stage 2: Link is built between delegating router and CPE Stage 3: CPE uses a solicit message to find DHCPv6 servers Stage 4: Delegating router responds with an offer Stage 5: CPE issues a request to obtain /48 prefix Stage 6: Delegating router issues a reply with prefix Stage 7: CPE configures /64 networks

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Example DHCPv6 Prefix Delegation (Cont.) Host A Host B ISP Network and Internet Delegating Router CPE Router

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Configure the Delegating Router How to Implement DHCPv6 Prefix Delegation in an IPv6 Environment f0/1 Provider edge: Configure pool of prefixes for allocation. Enable DHCPv6 server on CPE-facing interface. f0/0 ISP Network and Internet Delegating Router CPE Requesting Router f0/2

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Provider edge: Configure pool of prefixes for allocation. Enable DHCPv6 server on CPE-facing interface. Configure the Delegating Router How to Implement DHCPv6 Prefix Delegation in an IPv6 Environment (Cont.) f0/1 f0/0 ISP Network and Internet Delegating Router CPE Requesting Router f0/2

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Customer router: Configure delegating router-facing interface as DHCPv6 client. Configure host-facing interfaces to assign /64 address and prefix for autoconfiguration Configure the CPE How to Implement DHCPv6 Prefix Delegation in an IPv6 Environment (Cont.) f0/1 f0/0 ISP Network and Internet Delegating Router f0/2 CPE Requesting Router

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Troubleshoot Prefix Delegation (Delegating Router) How to Implement DHCPv6 Prefix Delegation in an IPv6 Environment (Cont.) show ipv6 interface brief show ipv6 dhcp pool show ipv6 dhcp binding show ipv6 dhcp interface f0/1 f0/0 ISP Network and Internet Delegating Router CPE Requesting Router f0/2

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v show ipv6 interface brief show ipv6 dhcp interface Troubleshoot Prefix Delegation (Requesting Router) How to Implement DHCPv6 Prefix Delegation in an IPv6 Environment (Cont.) f0/1 f0/0 ISP Network and Internet Delegating Router f0/2 CPE Requesting Router

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v Summary DHCPv6 improves on DHCPv4 in several ways, including the use of multicast, rather than broadcast, for client-server address negotiations. DHCPv6 prefix delegation allows an upstream router to delegate an entire prefix, rather than a single address, to a downstream router. Configuring DHCPv6 prefix delegation involves configuring the provider edge and CPE routers, then troubleshooting.

© 2006 Cisco Systems, Inc. All rights reserved.IP6FD v