Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide - Manual (Page 588)

FIGURE 36 Switch 1 and Switch 2 configured as VRRP virtual routers for redundant network access
for Host1
The dashed box 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 through 255. In
this example, the VRID is 1.
NOTE
You can provide more redundancy by also configuring a second VRID with Switch 2 as the Owner and
Switch 1 as the Backup. This type of configuration is sometimes called Multigroup VRRP.
Virtual router ID
A virtual router ID ( VRID) consists of one Master router and one or more Backup routers. The Master
router is the router that owns the IP addresses 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 addresses associated with the
VRID but provides the backup path if the Master router becomes unavailable.
Virtual router MAC address
Notice the MAC address associated with VRID1 in VRRP overview on page 586. 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.
When you configure a VRID, the software automatically assigns its MAC address. When a VRID
becomes active, the Master router broadcasts a gratuitous ARP request containing the virtual router
MAC address for each IP address associated with the virtual router. In
VRRP overview on page 586,
Switch 1 sends a gratuitous ARP request with MAC address 00-00-5E-00-01-01 and IP address
Virtual router ID
588 FastIron Ethernet Switch Layer 3 Routing Configuration Guide
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