IPv6-GLBP Configuration Example

First Hop Redudancy for IPv6 can be achieved via different protocols like HSRP, GLBP or VRRP. The Gateway Load Balancing Protocol (GLBP) feature provides automatic router backup for IPv6 hosts configured with a single default gateway on an IEEE 802.3 LAN. GLBP provides benefits of Load Sharing, Multiple Virtual Routers, Preemption and Authentication.

Prerequisite

1. IPv6 Addressing Scheme
2. Understaing of First Hop Redudancy Routinng Protocols

Background

In this document, Gateway Load BalancingProtocol (GLBP) is configured on the LAN interface (FastEthernet 0/0) of Router R3 and R4. These two routers are advertised with a IPv6 network of 1111:11:11:11::11/64 by ISP-Router. As both the routers have reachability to ISP-Router, they are acting as a gateway to reach ISP network and providing redundancy.

The virtual IPv6 address used is FE80::260:3EFF:FE11:6770 by command glbp 11 ipv6 FE80::260:3EFF:FE11:6770. Router R2 acting as a host is configured with a default static route pointing toward the Virtual IPv6 Address. The command is ipv6 route ::/0 FastEthernet0/0 FE80::260:3EFF:FE11:6770.

Summary Steps

Router# conf t

Router(config)# interface FastEthernet0/0

Router(config-if)# ipv6 address 2011:ABC:11:11::3/64

Router(config-if)#  glbp 11 ipv6 FE80::260:3EFF:FE11:6770

Router(config-if)#  glbp 11 priority 200

Router(config-if)#  glbp 11 preempt

Note: All configurations are tested on Cisco 3745 Router running IOS 12.4(15)T advance ip services (c3745-advipservicesk9-mz.124-15.T14).

Topology Diagram

Configuration

Interface Configuration

Router Configuration

Please see the attached files for complete configuration.

Verification Commands

show glbp

ping ipv6

Note: The host,R2, is able to reach the ISP network 1111:11:11:11::11.

debug ipv6 packet

Please see attached file https://supportforums.cisco.com/docs/DOC-23397