Created on
06-28-2006
12:00 AM
Edited on
01-06-2025
03:25 AM
By
Jean-Philippe_P
Description
This article describes the HA Cluster virtual MAC addresses.
Scope
FortiGate.
Solution
The virtual MAC address is determined based on the following formula on virtual cluster 1:
<group-prefix>:<group-id_hex>:(<vcluster_integer> + <idx>)
Where:
<group-prefix> is determined by the set of group IDs:
Set 1: group IDs 0 - 255: group prefix 00:09:0f:09.
Set 2: group IDs 256 - 511: group prefix e0:23:ff:fc.
Set 3: group IDs 512 - 767: group prefix e0:23:ff:fd.
Set 4: group IDs 768 - 1023: group prefix e0:23:ff:fe.
To check the group-id, use 'get system ha'.
<group-id_hex> is the HA Group ID for the cluster converted to hexadecimal. The following table lists the virtual MAC address set for each group ID.
Integer Group ID | Hexadecimal Group ID |
---|---|
0 | 00 |
1 | 01 |
2 | 02 |
3 | 03 |
4 | 04 |
... | ... |
10 | 0a |
11 | 0b |
... | ... |
63 | 3f |
... | ... |
255 | ff |
<vcluster_integer> is 0 for virtual cluster 1 and 20 for virtual cluster 2. If virtual domains are not enabled, HA sets the virtual cluster to 1 and by default, all interfaces are in the root virtual domain. Including virtual cluster and virtual domain factors in the virtual MAC address formula means that the same formula can be used whether or not virtual domains and virtual clustering is enabled.
<idx> is the index number of the interface. Interfaces are numbered from 0 to x (where x is the number of interfaces). Interfaces are numbered according to their map order. The first interface has an index of 0. The second interface in the list has an index of 1 and so on.
For example:
When the HA group ID is 0 (i.e default) & the mgmt1 phy_index= 0, itf_name= mgmt1, Physical mac=e0.23.ff.a0.98.04,
then the Virtual-mac=00.09.0f.09.00(group ID is 0).00(vcluster_integer for vcluster 1 is '0' and index of the interface is 0).
If the same interface is changed to virtual cluster 2, the MAC address should add 8 on the second last digit, i.e., add 80 in hexadecimal:
Add 80 in hexadecimal: 00 -> 80.
Therefore it is necessary to follow the virtual MAC address: 00.09.0f.09.00.80.
Note: Starting from FortiOs v7.6.0, there are three methods available for assigning Virtual MAC address.
config system interface
edit <interface>
set virtual-mac <mac_address>
next
end
config system ha
set group-id 25
set auto-virtual-mac-interface "port1" "port2" "port8" "dmz"
end
Related documents:
Troubleshooting Tip: Verifying physical and HA Virtual MAC addresses of FortiGate interfaces
Cluster virtual MAC addresses
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.
Copyright 2025 Fortinet, Inc. All Rights Reserved.