HP ProCurve 3500yl Release Notes page 83

When OSPF is Also Enabled on the VRRP Routers
When OSPF is enabled on the routers and a Fail-back event occurs, the Owner router immediately
takes control of the virtual IP address and provides the default gateway functionality. If OSPF has
not converged, the route table in the Owner router may not be completely populated. When the hosts
send packets to the default gateway, the Owner router may not know where to send them and packets
may be dropped.
C a u t i o n
While you can run OSPF and VRRP concurrently on a router, it is best not to run VRRP with other
routing protocols such as RIP or OSPF on the same interface or VLAN as this can create operational
issues.
Configuring the Preempt Delay Timer
The VRRP Pre-empt Delay Timer (PDT) allows you to configure a period of time before the Owner
router takes back control of the virtual IP address. It does not transition to the Master state until the
timer period expires. The timer value configured should be long enough to allow OSPF convergence
following OSPF updates.
The PDT is applied only during initialization of the router, that is, when the router is rebooting with
the VRRP parameters present in the startup config file.
Syntax: [no] preempt-delay-time <1-600 >
Allows you to specify a time in seconds that the Owner router will wait before taking
control of the virtual IP address and beginning to route packets. You can configure
the timer on VRRP Owner and Backup routers.
Note: If you have configured the Preempt Delay Timer with a non-zero value, you
must use the no form of the command to change it to 0 (zero).
Default: 0 (zero) seconds.
Note
If the PDT is active for a virtual router, you cannot change the router's mode from Owner to Backup
or Backup to Owner. To change the mode, make the PDT inactive and then reconfigure the mode.
For example:
ProCurve(config)# no vlan 16 vrrp vrid 23 preempt-delay time 12
Enhancements
Release K.13.02 Enhancements
72