What is a MAC address; where does it appear in TR7?

Short answer

A MAC address is the 48-bit hardware address of a network interface at the L2 level (e.g. 00:1a:2b:3c:4d:5e); devices in the same L2 segment forward frames to each other with this address, and which MAC an IP address is on is found with ARP. The MAC address is not carried beyond a router. In TR7, the MAC Address column on the Settings → Device Management → Hardware Management screen lists the addresses of the physical interfaces; in a cluster, this column is split in two and the MAC addresses of the two devices are seen side by side. On the Network → Interfaces screen, when an interface is selected, a MAC Address row is seen for each device in the Details tab of the preview panel. In Firewall rules, a rule based on the source MAC is written by selecting MAC Address as the Source. An interface of the V-ETH type works with its own MAC address, independent of the parent interface.

Where It Is Used in TR7

Where	Field / label	What for
Settings → Device Management → Hardware Management	The MAC Address column (in a cluster, two columns with the name of each device)	Physical interface inventory; comparing the cabling of the two devices in a cluster
Network → Interfaces → interface → preview → Details	The MAC Address row (Details)	The MAC address of the interface read from the system, per device
Network → Firewall → Add	Source = MAC Address	Applying the rule to a specific source MAC (or, with the inversion switch, to the sources other than it)
Network → Interfaces → Add Interface	Type = V-ETH	Creating a virtual interface with an independent MAC address on a parent interface
Network → Interfaces → Add Interface → VXLAN → Details	MAC Learning (enabled by default)	Dynamic learning of the MAC addresses of the remote endpoints
WEB-CLI	sys-cmd ip show address (ip show address)	The MAC address of the interface in the link/ether line of the output

Common Misconceptions

• "The MAC address is seen over the internet." MAC is used only in the local L2 segment; a packet passing through a router is forwarded with the MAC address of that router.
• "The MAC of an interface always comes from the physical card." Virtual interfaces such as V-ETH work with their own MAC addresses.
• "The MAC address can be changed in the interface form." There is no MAC field in the Add interface and Edit interface forms; the MAC address is only displayed in Hardware Management and in the preview panel.

How it is done in the documentation

• Hardware Management · The Hardware Management Screen
• Interfaces List · Details
• Firewall · MAC Address

Related questions

• What is ARP; how does it relate to VIP failover and the Spoofing setting in TR7?
• What is an interface; what is the difference between a physical (ETH) interface and a virtual interface?
• Do TR7 and the backends have to be on the same L2 network?