Users Guide

The example shows a typical network configuration using VRRP. Instead of configuring the hosts on network 10.10.10.0 with the
IP address of either Router A or Router B as the default router, the default router of all hosts is set to the IP address of the
virtual router. When any host on the LAN segment requests Internet access, it sends packets to the IP address of the virtual
router.
Router A is configured as the master router with the virtual router IP address and sends any packets addressed to the virtual
router to the Internet. Router B is the backup router and is also configured with the virtual router IP address.
If Router A, the master router, becomes unavailable (the connection between the LAN segment and Router A on ethernet 1/1/6
goes down), Router B, the backup router, automatically becomes the master router and responds to packets sent to the virtual
IP address. All workstations continue to use the IP address of the virtual router to transmit packets destined to the Internet.
Router B receives and forwards packets on interface ethernet 1/1/5. Until Router A resumes operation, VRRP allows
Router B to provide uninterrupted service to the users on the LAN segment accessing the Internet.
When the interface that Router A uses to provide gateway services (ethernet 1/1/7) goes down, Router B does not take over
automatically. For Router B to become the master router, you must configure interface tracking. When you configure tracking
on the interface and the interface goes down, the VRRP group's priority decreases. The lowered priority of the VRRP group
triggers an election and Router B becomes the master router. See Interface/object tracking for more information.
Create virtual router
VRRP uses the VRID to identify each virtual router configured. Before using VRRP, you must configure the interface with the
primary IP address and enable it.
● Create a virtual router for the interface with the VRRP identifier in INTERFACE mode, from 1 to 255.
vrrp-group vrrp-id
● Delete a VRRP group in INTERFACE mode.
no vrrp-group vrrp-id
Configure VRRP
OS10(config)# interface ethernet 1/1/5
OS10(conf-if-eth1/1/5)# vrrp-group 254
Verify VRRP
OS10(conf-eth1/1/5-vrid-254)# do show running-configuration
...
!
interface ethernet 1/1/5
ip address 10.10.10.1/24
!
vrrp-group 254
no shutdown
...
Group version
Configure a VRRP version for the system. Define either VRRPv2 — vrrp version 2 or VRRPv3 — vrrp version 3.
● Configure the VRRP version for IPv4 in INTERFACE mode.
vrrp version
Configure VRRP version 3
OS10(config)# vrrp version 3
1. Set the switch with the lowest priority to vrrp version 2.
2. Set the switch with the highest priority to vrrp version 3.
3. Set all switches from vrrp version 2 to vrrp version 3.
Layer 3
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