When the tm.macmasqaddrpervlan database variable is enabled, the BIG-IP system generates a unique MAC address for each VLAN by modifying the base MAC masquerade address of the traffic group. It replaces the last two bytes (octets) of the base MAC address with the 16-bit hexadecimal representation of the VLAN ID.

In this scenario:

Base MAC address: 02:12:34:56:00:00

VLAN ID: 1501 (decimal)

The decimal VLAN ID 1501 is converted to hexadecimal, which is 0x05DD. The BIG-IP system then replaces the last two bytes (00:00) of the base MAC with 05:DD. The resulting MAC address is 02:12:34:56:05:DD.

A. 02:12:34:56:01:15: This option incorrectly uses parts of the decimal VLAN ID (01 and 15) instead of the proper hexadecimal conversion.

B. 02:12:34:56:dd:05: This option incorrectly reverses the byte order (endianness) of the hexadecimal representation of the VLAN ID.

D. 02:12:34:56:15:01: This option incorrectly treats the decimal digits 15 and 01 as separate hexadecimal values without performing the full conversion of 1501.

1. F5 Networks Knowledge Base, K13502: Configuring MAC masquerade (11.x - 17.x)

Section: "Configuring a unique MAC masquerade address for each VLAN"

Content: "When you enable the tm.macmasqaddrpervlan database variable, the BIG-IP system uses the VLAN tag as the last two bytes of the traffic group MAC masquerade address. For example, if the traffic group MAC masquerade address is 02:01:02:03:04:00 and the VLAN tag is 10 (0x0a), the BIG-IP system uses 02:01:02:03:00:0a as the MAC masquerade address for the VLAN." This directly confirms the calculation method.

2. F5 Networks BIG-IP TMOS: Implementations, Version 15.1

Chapter: "Implementing High Availability"

Section: "Understanding MAC Masquerade"

Content: The documentation describes the purpose of MAC masquerade and mentions the tm.macmasqaddrpervlan variable as a solution for environments where a single MAC address across multiple VLANs is problematic, implying a per-VLAN modification mechanism.