Owner's Manual

590 | Chapter 19. VRRP
NETGEAR 8800 User Manual
Figure 59. Simple VRRP Network
In Figure 59, a virtual router is configured on Switch A and Switch B using these parameters:
• VRID is 1.
• MAC address is 00-00-5E-00-01-01.
• IP address is 192.168.1.3.
Switch A is configured with a priority of 255. This priority indicates that it is the master router.
Switch B is configured with a priority of 100. This indicates that it is a backup router.
The master router is responsible for forwarding packets sent to the virtual router. When the
VRRP network becomes active, the master router broadcasts an ARP request that contains
the virtual router MAC address (in this case, 00-00-5E-00-01-01) for each IP address
associated with the virtual router. Hosts on the network use the virtual router MAC address
when they send traffic to the default gateway.
The virtual router IP address is configured to be the real interface address of the IP address
owner. The IP address owner is usually the master router. The virtual router IP address is
also configured on each backup router. However, in the case of the backup router, this IP
address is not associated with a physical interface. Each physical interface on each backup
router must have a unique IP address. The virtual router IP address is also used as the
default gateway address for each host on the network.
If the master router fails, the backup router assumes forwarding responsibility for traffic
addressed to the virtual router MAC address. However, because the IP address associated
with the master router is not physically located on the backup router, the backup router
cannot reply to TCP/IP messages (such as pings) sent to the virtual router.
The configuration commands for switch A are as follows:
configure vlan vlan1 ipaddress 192.168.1.3/24
create vrrp vlan vlan1 vrid 1
configure vrrp vlan vlan1 vrid 1 prioirty 255
configure vrrp vlan vlan1 vrid 1 add 192.168.1.3
enable vrrp
EX_068
Switch A
Switch A = Master
VRID = 1
Virtual router IP address = 192.168.1.3
MAC address = 00-00-5E-00-01-01
Priority = 255
Default Gateway = 192.168.1.3
192.168.1.3
Switch B
Switch B = Backup
VRID = 1
Virtual router IP address = 192.168.1.3
MAC address = 00-00-5E-00-01-01
Priority = 100
192.168.1.5