Introduction
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
- IPv6 Addressing Scheme
- Understaing of First Hop Redudancy Routinng Protocols
Background
In this document, Gateway Load Balancing Protocol (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
