Can we extend the default MAC Prefix in the Cluster

[deepakvidyadharan]

https://pve.proxmox.com/pve-docs/datacenter.cfg.5.html - Documentation says that it’s highly recommended that you extend the default MAC prefix, or generate a custom (valid) one, to reduce the chance of MAC collisions. For example, add a separate extra hexadecimal to the Proxmox OUI for each cluster, like BC:24:11:0 for the first, BC:24:11:1 for the second, and so on.

Tried to update the MAC address Prefix to BC:24:11:00 however this is not accepting. We are using the PVE version 8.4.0.

Is it possible to use the 4 Octets for the MAC address Prefix ?

 

[bbgeek17]

Hi @deepakvidyadharan , welcome to the forum.

One way to find the answer to your question is to check the code:
root@pve-1:/usr/share/perl5/PVE# grep -R mac|grep prefix
...
DataCenterConfig.pm: if ($mac_prefix !~ m/^[a-f0-9][02468ace](?::[a-f0-9]{2}){0,2}:?$/i) {
...

Quick AI summary:

The string must start with one or more pairs of hex digits.

The second hex digit of the first byte must be even, which enforces that it’s a valid unicast MAC address prefix.

After the first byte, it can have up to two more bytes (:XX), making it 1–3 bytes long.

It may optionally end with a colon (:).

Example matches:

00:
aa:bb:
0c:12:34:
02:1a:ff

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