How to Calculate a Virtual MAC Address
57697
Created On 09/25/18 19:24 PM - Last Modified 05/05/25 18:49 PM
Objective
In Layer 3 mode, a virtual MAC address is created for the configured floating IP address and ARP load sharing IP address interfaces.
Environment
- NGFW Firewall
- High Availability
Procedure
The format of the virtual MAC is 00-1B-17:00: xx: yy, where;
- 00-1B-17: The vendor ID (This value may be different depending on PAN-OS version or Platform)
- 00: Fixed at 00
- xx: The value representation is as follows
- yy: The interface ID
When a new active device takes over, Gratuitous ARPs are sent from each of the connected interfaces of the functional device. This informs the connected Layer-2 switches of the new location for the virtual MAC addresses.