New VM MAC address restriction

jimmymiller

Maybe this has been answered somewhere else and my quick search couldn't work out the keywords.

I'm looking to restrict (or at least set a default) for MAC address usage in XO/XCP-ng. In VMware, MAC addresses were limited to 00:50:56 (vCenter created) or 00:0c:29 (ESXi created) as a default. We currently use those first 6 octets to distinguish VMs from baremetal resources discovered on our network. I'm curious if there is a means of doing something like that as a default, in a template, etc. I understand individuals may be able to change it after the fact, but if I can set a standard for those first 6 inside XO/XCP-ng, it will make our VM create processes work better with our existing network discovery processes.

olivierlambert

Hey

Thanks for your feedback, asking around

olivierlambert

That's the part we need to change:
https://github.com/xapi-project/xen-api/blob/master/ocaml%2Fxapi%2Fxapi_vif_helpers.ml#L209

But I think using the Xen OUI by default (00:16:3e) could leak information on the hypervisor used So we need to make it configurable. A XAPI issue will come next week and we'll see how to work with it

olivierlambert

Pinging @BenjiReis as a reminder so we can discuss this somewhere next week

jimmymiller

@olivierlambert Did anything ever come of this?

olivierlambert

It's doable but it's not yet on top priority list to our work on getting 8.3 released. But IIRC it's in our backlog, right @BenjiReis ?

BenjiReis

It's in the backlog indeed but I don't know when the ETA to start this.
I guess an issue in the xen-api repo would be a good first step to see what the XAPI team think of the feature.

mdraugh

I'm in the same boat -- this totally-random-MAC system is causing serious problems with my system inventory. Can we get this moved up on the priority list somehow? It seems like a pretty simple change.

splastunov

It is not a problem at all.

You can always set MAC manually, or create VIF with certain MAC via XAPI or cli.

Link to XAPI https://xapi-project.github.io/xen-api/classes/vif.html
check create method.

Cli command
xe vif-create vm-uuid=<VM UUID> network-uuid=<NETWORK UUID> device=<ETHERNET INTERFACE NUMBER> mac=<MAC ADDRESS>
Device could be in range 0-15
MAC in format XX:XX:XX:XX:XX:XX

After you need "activate" new VIF by command
xe vif-plug uuid=<VIF UUID>
If VM does not running xe-guest-tools you have to switch off VM and power it on again to activate new VIF.

mdraugh

@splastunov -- not a problem if you have the time and can train all your people (and have them remember each time) to do this manual workaround and independently select a unique MAC, which will require having a list they can easily check (and keep updated!) so they don't duplicate a MAC. On the other hand, every other virtualization platform I've used has either had a fixed OUI or a settable OUI, so I don't think this is ridiculous to ask for.

splastunov

@mdraugh sure.

As workaround you can create simple table with MAC-IP-VM fields, and simple script to deploy new VM with first "free" MAC. Yes, it sounds like to develop your own XO, but I belive it should help alot.

olivierlambert

It's not ridiculous, but it's always things to manage in our backlog. I would love to do everything at once (even if we grow fast, the backlog is still larger than our workforce). At least, it's planned.

tuxen

FYI, Xen has a registered OUI: 00:16:3E

edit: I didn't read @olivierlambert previous post mentioning the OUI

Source: https://www.macvendorlookup.com