VRRP Configuration Command Reference
436 Router Configuration Guide
Multiple unique (different ip-address) host-unreachable event nodes can be configured within the 
priority-event node to a maximum of 32 events. 
The host-unreachable command can reference any valid local or remote IP address. The ability to 
ARP a local IP address or find a remote IP address within a route prefix in the route table is considered 
part of the monitoring procedure. The host-unreachable priority event operational state tracks ARP 
or route table entries dynamically appearing and disappearing from the system. The operational state 
of the host-unreachable event are listed in Table 37.
Unlike other priority event types, the host-unreachable priority event monitors a repetitive task. A 
historical evaluation is performed on the success rate of receiving ICMP echo reply messages. The 
operational state takes its cleared and set orientation from the historical success rate. The informational 
portion of the operational state is derived from the last attempt’s result. It is possible for the previous 
attempt to fail while the operational state is still cleared due to an insufficient number of failures to 
cause it to become set. It is also possible for the state to be set while the previous attempt was 
successful.
Table 37: Host Unreachable Operational States
Host Unreachable 
Operational State
Description
Set – no ARP No ARP address found for ip-addr for drop-count consecutive attempts. 
Only applies when IP address is considered local.
Set – no route No route exists for ip-addr for drop-count consecutive attempts. Only 
when IP address is considered remote.
Set – host unreachable ICMP host unreachable message received for drop-count consecutive 
attempts.
Set – no reply ICMP echo request timed out for drop-count consecutive attempts.
Set – reply received Last ICMP echo request attempt received an echo reply but historically 
not able to clear the event.
Cleared – no ARP No ARP address found for ip-addr - not enough failed attempts to set the 
event.
Cleared – no route No route exists for ip-addr - not enough failed attempts to set the event.
Cleared – host 
unreachable
ICMP host unreachable message received - not enough failed attempts 
to set the event.
Cleared – no reply ICMP echo request timed out - not enough failed attempts to set the 
event.
Cleared – reply 
received
Event is cleared - last ICMP echo request received an echo reply.