LLDP on a virtual wire allows neighboring devices to
detect the firewall.
Virtual wire interfaces can use LLDP to
discover neighboring devices and their capabilities, and LLDP allows
neighboring devices to detect the presence of the firewall in the
network. LLDP makes troubleshooting easier especially on a virtual
wire, where the firewall would typically go undetected by a ping
or traceroute passing through the virtual wire. LLDP provides a
way for other devices to detect the firewall in the network. Without
LLDP, it is practically impossible for network management systems
to detect the presence of a firewall through the virtual link.