What is the unknown pak counter actually counting?
Problem or Goal:
The 'unknown pak' counter in the interface counter tables ('get counter stat' output) is for any packets with an Ethernet type that the firewall does not recognize. Examples would be Spanning Tree or proprietary Cisco protocols that the firewall does not pass or is capable of reading. When the firewall sees a packet with a Ethernet type it does not recognize, it will drop the packet and increment the 'unknown pak' counter.