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[vSRX] How is the new MAC address derived for ge/gig interfaces after enabling chassis cluster?



Article ID: KB33244 KB Last Updated: 21 Nov 2018Version: 2.0

When enabling the chassis cluster feature in vSRX, the revenue ports (ge- ports) interface MAC addresses (Hardware address) change from the original. The newly assigned addresses are different from the addresses assigned by the hypervisor.


It is expected that the ge interface Hardware MAC addresses are changed after enabling the chassis cluster in vSRX. Below is the logic for how the new Hardware MAC address is derived:

  1. First three octets will be constant and will always be   4C:96:14:

  2. Fourth and fifth octet will be taken from the fxp0 interface MAC address. It will use the fifth and sixth octet from the fxp0 MAC address respectively.

  3. The last octet will be same as indexing of ge interface, for ex. 00 for ge-0/0/0 or for ge-7/0/0


 root> show interfaces fxp0 | match ha
   Current address: 00:50:56:95:14:cd, Hardware address: 00:50:56:95:14:cd <-- fxp0 MAC address. It does not change before or after the enabling chassis cluster
 root> show interfaces ge-7/0/0 | match ha
   Current address: 4c:96:14:14:cd:b0, Hardware address: 4c:96:14:14:cd:00 <-- ge-7/0/0 MAC address after enabling the chassis cluster
 root> show interfaces ge-7/0/1 | match ha
   Current address: 00:10:db:ff:10:00, Hardware address: 4c:96:14:14:cd:01 <-- ge-7/0/1 MAC after enabling the chassis cluster

In the above example, it can be seen that the first three octets are constant 4c:96:14. The fourth and fifth are the same as the fifth and sixth of fxp0. The last octet is 00 or 01 depending on the last index of ge-7/0/0 or ge-7/0/1.

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