Why is the K-Series MAC address the source of Port 137 traffic Logged on the Firewall?
Why is the routers MAC address the source of port 137 traffic logged by the firewall?
Routers rebuild the Ethernet frame when routing between VLANs and replace the source MAC of the client with the MAC of the interface facing the firewall. Traffic routed from inside the network will be sent to the firewall with the router's MAC address. Port 137 is used for NetBIOS,but the behavior is the same for all routed traffic regardless of the port used.