Configuring VRRP and VRRPE

Figure 12.2 shows the same example network shown in Figure 12.1, but with a VRRP virtual router configured on Router1 and Router2.

Internet or

enterprise Intranet

e 2/4

Internet or

enterprise Intranet

e 3/2

VRID1

Router1 = Master

IP address = 192.53.5.1

e 1/6 192.53.5.1

 

VRID1

192.53.5.3 e 1/5

Router2 = Backup

 

IP address = 192.53.5.1

MAC address = 00-00-5E-00-01-01 Priority = 255

Track port = e 2/4

Track priority = 20

MAC address = 00-00-5E-00-01-01 Priority = 100

Track port = e 3/2

Track priority = 19

Host1

Default Gateway 192.53.5.1

Figure 12.2 Router1 and Router2 are configured as a VRRP virtual router to provide redundant network access for Host1

The dashed box in Figure 12.2 represents a VRRP virtual router. When you configure a virtual router, one of the configuration parameters is the virtual router ID (VRID), which can be a number from 1 – 255. In this example, the VRID is 1. The VRID must be unique within the LAN. VRIDs do not cross LAN boundaries. Thus, there is no restriction against reusing a VRID with a different address mapping on different LANs.

NOTE: You can provide more redundancy by also configuring a second VRID with Router2 as the Owner and Router1 as the Backup. This type of configuration is sometimes called Multigroup VRRP.

Virtual Router ID (VRID)

A VRID consists of one Master router and one or more Backup routers. The Master router is the router that owns the IP address(es) you associate with the VRID. For this reason, the Master router is sometimes called the “Owner”. Configure the VRID on the router that owns the default gateway interface. The other router in the VRID does not own the IP address(es) associated with VRID but provides the backup path if the Master router becomes unavailable.

Virtual Router MAC Address

Notice the MAC address associated with VRID1. The first five octets of the address are the standard MAC prefix for VRRP packets, as described in RFC 2338. The last octet is the VRID. THE VRID number becomes the final octet in the virtual MAC address associated with the virtual router.

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