Contents

Introduction

Prerequisites

Requirements

Components Used

Configure

Network Diagram

Configurations

Verify

Troubleshoot on Client

Related Information

Introduction

This document describes Prefix Delegation configuration example in scenarios where Layer 2 Tunnelling Protocol Network Server (LNS)  delegates an IPv6 prefix to the Client router over Virtual Private Dialup Network (VPDN) Tunnel built between the Layer 2 Tunnelling Protocol Access Concentrator (LAC) and LNS.

Prerequisites

Requirements

Cisco recommends that you have knowledge of End-to-End Layer 1 connectivity that is UP

Components Used

This document is not restricted to specific software and hardware versions.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Configure

Note: Use the Command Lookup Tool (registered customers only) in order to obtain more information on the commands used in this section.

Network Diagram

This document uses this network setup:

Configurations

Client Configuration:

An example of the configuration on the Client router is shown here:

ipv6 unicast-routing

!

interface Ethernet0/0

no ip address

pppoe enable group global

pppoe-client dial-pool-number 1

end

interface Dialer1

ip address negotiated

encapsulation ppp

dialer pool 1

ipv6 address FE80::1234 link-local

ipv6 address autoconfig

ipv6 enable

no ipv6 nd ra suppress

ipv6 dhcp client pd my-prefix1

no keepalive

ppp chap hostname test@cisco.com

ppp chap password 0 cisco

no cdp enable

end

!

interface FastEthernet0/2

description -  This interface is connected to the LAN segment

no ip address

ipv6 address my-prefix1 ::1/64

ipv6 enable

LAC Configuration:

An example of the configuration on the LAC  is shown here:

hostname LAC

!

vpdn enable

!

vpdn-group 1

request-dialin

protocol l2tp

domain cisco.com

initiate-to ip 192.168.1.2

source-ip 192.168.1.1

no l2tp tunnel authentication

!

bba-group pppoe global

virtual-template 1

!

interface Ethernet0/0

no ip address

pppoe enable group global

!

interface Ethernet1/0

ip address 192.168.1.1 255.255.255.0

!

interface Virtual-Template1

no ip address

ppp authentication chap

!

LNS Configuration:

An example of the configuration on the LNS  is shown here:

ipv6 unicast-routing

!

vpdn enable

!

vpdn-group 1

accept-dialin

protocol l2tp

virtual-template 1

terminate-from hostname LAC

vpn vrf test

lcp renegotiation on-mismatch

no l2tp tunnel authentication

!

username test@cisco.com password cisco

interface Ethernet1/0

ip vrf forwarding test

ip address 192.168.1.2 255.255.255.0

negotiation auto

cdp enable

end

interface Virtual-Template1

ip address 10.1.1.1 255.255.255.0

ipv6 enable

ipv6 dhcp server AAA

peer default ip address pool local

peer default ipv6 pool PPPOE_POOL6

no keepalive

ppp authentication chap

!

ipv6 dhcp pool AAA

prefix-delegation pool DHCPv6Pool

!

ipv6 local pool PPPOE_POOL6 2001:DB8:5AB:10::/60 64

!

ip local pool local 10.1.1.2 10.1.1.100

!

ipv6 local pool DHCPv6Pool 2A02:838F:F880::/42 56

!

Verify

Client#show ipv6 interface brief FastEthernet0/2

FastEthernet0/2              [up/up]

FE80::205:FF:FE77:2C1B

2A02:838F:F880::1

Client#show ipv6 interface brief dialer1

Dialer1                [up/up]

FE80::1234

2001:DB8:5AB:10::1234

Troubleshoot on Client

These debugs assist in debugging the issue:

debug ppp negotiation

debug ipv6 dhcp detail

Client#show debug

PPP:

PPP protocol negotiation debugging is on

IPv6 DHCP:

IPv6 DHCP debugging is on (detailed)

This a snippet of debug ipv6 dhcp detail on the Client router after PPP Negotiation has been completed and respective Virtual-Access is UP.

*Jun 27 15:08:53.019: %LINEPROTO-5-UPDOWN: Line protocol on Interface Virtual-Access2, changed state to up

*Jun 27 15:09:03.711: IPv6 DHCP: detailed packet contents

*Jun 27 15:09:03.711:   src FE80::1234

*Jun 27 15:09:03.711:   dst FF02::1:2 (Dialer1)

*Jun 27 15:09:03.711:   type REQUEST(3), xid 1849347

*Jun 27 15:09:03.711:   option ELAPSED-TIME(8), len 2

*Jun 27 15:09:03.711:     elapsed-time 3202

*Jun 27 15:09:03.711:   option CLIENTID(1), len 10

*Jun 27 15:09:03.711:     00030001000500772C1B

*Jun 27 15:09:03.711:   option ORO(6), len 6

*Jun 27 15:09:03.711:     IA-PD,DNS-SERVERS,DOMAIN-LIST

*Jun 27 15:09:03.711:   option SERVERID(2), len 10

*Jun 27 15:09:03.711:     000300017CAD74F9EB00

*Jun 27 15:09:03.711:   option IA-PD(25), len 41

*Jun 27 15:09:03.711:     IAID 0x000B0001, T1 0, T2 0

*Jun 27 15:09:03.711:     option IAPREFIX(26), len 25

*Jun 27 15:09:03.711:       preferred 0, valid 0, prefix 2A02:838F:F880::/56

*Jun 27 15:09:03.711: IPv6 DHCP: Sending REQUEST to FF02::1:2 on Dialer1

*Jun 27 15:09:03.711: IPv6 DHCP: Received REPLY from FE80::7EAD:74FF:FEF9:EB00 on Dialer1

*Jun 27 15:09:03.711: IPv6 DHCP: detailed packet contents

*Jun 27 15:09:03.711:   src FE80::7EAD:74FF:FEF9:EB00 (Dialer1)

*Jun 27 15:09:03.711:   dst FE80::1234 (Dialer1)

*Jun 27 15:09:03.711:   type REPLY(7), xid 1849347

*Jun 27 15:09:03.711:   option SERVERID(2), len 10

*Jun 27 15:09:03.711:     000300017CAD74F9EB00

*Jun 27 15:09:03.711:   option CLIENTID(1), len 10

*Jun 27 15:09:03.711:     00030001000500772C1B

*Jun 27 15:09:03.711:   option IA-PD(25), len 41

*Jun 27 15:09:03.711:     IAID 0x000B0001, T1 302400, T2 483840

*Jun 27 15:09:03.711:     option IAPREFIX(26), len 25

*Jun 27 15:09:03.711:       preferred 604800, valid 2592000, prefix 2A02:838F:F880::/56

*Jun 27 15:09:03.711: IPv6 DHCP: Processing options

*Jun 27 15:09:03.711: IPv6 DHCP: Adding prefix 2A02:838F:F880::/56 to my-prefix1

*Jun 27 15:09:03.711: IPv6 DHCP: T1 set to expire in 302400 seconds

*Jun 27 15:09:03.711: IPv6 DHCP: T2 set to expire in 483840 seconds

*Jun 27 15:09:03.711: IPv6 DHCP: DHCPv6 changes state from REQUEST to OPEN (REPLY_RECEIVED) on Dialer1

Related Information

- IPv6 Access Service: DHCPv6 Prefix Delegation

- Technical Support & Documentation - Cisco Systems