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Configuring VRRP and VRRPE
If the Owner becomes unavailable, but then comes back online, the Owner again becomes the Master router. The
Owner becomes the Master router again because it has the highest priority. The Owner always becomes the
Master again when the Owner comes back online.
NOTE: If you configure a track port on the Owner and the track port is down, the Owner’s priority is changed to
the track priority. In this case, the Owner does not have a higher priority than the Backup that is acting as Master
and the Owner therefore does not resume its position as Master. For more information about track ports, see
“Track Ports and Track Priority” on page 12-5.
By default, if a Backup is acting as the Master, and the Master is still unavailable, another Backup can “preempt”
the Backup that is acting as the Master. This can occur if the new Backup has a higher priority than the Backup
who is acting as Master. You can disable this behavior if you want. When you disable preemption, a Backup
router that has a higher priority than the router who is currently acting as Master does not preempt the new Master
by initiating a new Master negotiation. See “Backup Preempt” on page 12-18.
NOTE: Regardless of the setting for the preempt parameter, the Owner always becomes the Master again when
it comes back online.
Track Ports and Track Priority
The HP implementation of VRRP enhances the protocol by giving a VRRP router the capability to monitor the
state of the interfaces on the other end of the route path through the router. For example, in Figure 12.2 on
page 12-3, interface
e1/6 on Router1 owns the IP address to which Host1 directs route traffic on its default gateway. The exit path for
this traffic is through Router1’s e2/4 interface.
Suppose interface e2/4 goes down. Even if interface e1/6 is still up, Host1 is nonetheless cut off from other
networks. In conventional VRRP, Router1 would continue to be the Master router despite the unavailability of the
exit interface for the path the router is supporting. However, if you configure interface e1/6 to track the state of
interface e2/4, if e2/4 goes down, interface e1/6 responds by changing Router1’s VRRP priority to the value of the
track priority. In the configuration shown in Figure 12.2 on page 12-3, Router1’s priority changes from 255 to 20.
One of the parameters contained in the Hello messages the Master router sends to its Backups is the Master
router’s priority. If the track port feature results in a change in the Master router’s priority, the Backup routers
quickly become aware of the change and initiate a negotiation for Master router.
In Figure 12.2 on page 12-3, the track priority results in Router1’s VRRP priority becoming lower than Router2’s
VRRP priority. As a result, when Router2 learns that it now has a higher priority than Router1, Router2 initiates
negotiation for Master router and becomes the new Master router, thus providing an open path for Host1’s traffic.
To take advantage of the track port feature, make sure the track priorities are always lower than the VRRP
priorities. The default track priority for the router that owns the VRID IP address(es) is 2. The default track priority
for Backup routers is 1. If you change the track port priorities, make sure you assign a higher track priority to the
Owner of the IP address(es) than the track priority you assign on the Backup routers.
Suppression of RIP Advertisements for Backed Up Interfaces
The HP implementation also enhances VRRP by allowing you to configure the protocol to suppress RIP
advertisements for the backed up paths from Backup routers. Normally, a VRRP Backup router includes route
information for the interface it is backing up in RIP advertisements. As a result, other routers receive multiple
paths for the interface and might sometimes unsuccessfully use the path to the Backup rather than the path to the
Master. If you enable the HP implementation of VRRP to suppress the VRRP Backup routers from advertising the
backed up interface in RIP, other routers learn only the path to the Master router for the backed up interface.
Authentication
The HP implementation of VRRP can use simple passwords to authenticate VRRP packets. The VRRP
authentication type is not a parameter specific to the VRID. Instead, VRRP uses the authentication type
associated with the interfaces on which you define the VRID. For example, if you configure your router interfaces
to use a simple password to authenticate traffic, VRRP uses the same simple password and VRRP packets that
do not contain the password are dropped. If your interfaces do not use authentication, neither does VRRP.
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