Virtual wires support active/passive and active/active
HA and path monitoring. You can speed up HA failover for an active/passive
HA pair by pre-negotiating LACP and LLDP.
If you configure the firewall to perform path monitoring
Availability using a virtual wire path group, the firewall
attempts to resolve ARP for the configured destination IP address
by sending ARP packets out both of the virtual wire interfaces.
The destination IP address that you are monitoring must be on the
same subnetwork as one of the devices surrounding the virtual wire.
Virtual wire interfaces support both active/passive and active/active
HA. For an active/active HA deployment with a virtual wire, the
scanned packets must be returned to the receiving firewall to preserve
the forwarding path. Therefore, if a firewall receives a packet
that belongs to the session that the peer HA firewall owns, it sends
the packet across the HA3 link to the peer.
For PAN-OS 7.1 and later releases, you can configure the passive
firewall in an HA pair to allow peer devices on either side of the
firewall to pre-negotiate LLDP and LACP over a virtual wire before
an HA failover occurs. Such a configuration for LACP
and LLDP Pre-Negotiation for Active/Passive HA speeds up