Overview

General Information

VRRP priority control-policies manage VR backup router priorities. The policies override the base priority value, depending on NE events or conditions. You can configure a VRRP policy only for the non-owner VRRP instance; the same policy can be applied to IPv4 and IPv6 VRRP instances.

The main function of a VRRP priority-control policy is to define the conditions or events that affect the VR ability to communicate with outside hosts or portions of the network. When at least one of these events is true, the base priority for the VR instance is affected in one of two ways:

an explicit value is overridden
a value is subtracted from the sum of delta priorities

The result is the actual in-use priority for the VR instance. Any priority event may be configured as an explicit event or a delta event. The following table describes the policy events that you can configure using the NFM-P.

Table 55-1: VRRP policy events

Policy Event	Description
Host unreachable	Configures a host unreachable priority-control event that monitors the ability of a host to receive an ICMP echo reply packet from a specific IP host address. A host unreachable priority-control event creates a continuous ICMP echo request (ping) probe to the specified IP address. During ping failure, the event is considered to be set. During ping success, the event is considered to be cleared.
IPv6 Host unreachable	Configures an IPv6 host unreachable priority-control event that monitors the ability of a host to receive an ICMP echo reply packet from a specific IPv6 host address. An IPv6 host unreachable priority-control event creates a continuous ICMP echo request (ping) probe to the specified IPv6 address. During ping failure, the event is considered to be set. During ping success, the event is considered to be cleared.
LAG port down	Configures a LAG priority-control event that monitors the operational state of the links and each port in the LAG. When one or more of the ports enters the operational down state, the event is considered to be set. When all ports enter an operational up state, the event is considered to be clear.
Route unknown	Configures a route unknown priority-control event that monitors the existence of a specific active IP route prefix in the routing table. Route unknown defines a link between the VRRP priority-control policy and the RTM. The RTM registers the specified route prefix as monitored by the policy. If any change (add, delete, new next hop) occurs relative to the prefix, the policy is notified and takes action according to the priority event definition.
Port Down Events	Configures an override or adjustment to the base priority value of a VRRP VR instance depending on the operational state of the event. Port Down events can only be configured on the local definitions of VRRP policies.
Multi Chassis IPsec Non Forwarding Events	Configures an MC IPsec priority-control event that monitors the MEP state of a device. When the MEP state is down, the event is considered to be set. When the MEP state is up, the event is considered to be clear. For more information about MC IPsec, see Chapter 41, MC IPsec .

As priority events clear in the policy, the in-use priority can eventually be restored to the base priority value.