We are in the process of migrating this forum. A new space will be available soon. We are sorry for the inconvenience.

Confused About Lack of Virtual MACS in vRack...


goodbot2
15/05/2016, 01h01
I recently upgraded my single server (I have ambitions to add more servers soon). Because my new server has 2 NICs, I also upgraded to the freely available vRack. I know I won't be able to "take advantage" of what the vRack optimally offers until I have more than just 1 server... but I'm ambitious... and OVH support assured me that I can run a single server in the vRack environment with no problem.

I'm having a problem getting basic networking (external name resolution, pinging in or out) working on any of my VMs (in a Xen environment)... and I'm hitting a conceptual wall understanding this new vRack environment.

In my previous (non-vRack) OVH network environment, each of my IP's had a "virtual MAC" address assigned by the OVH datacenter and communicated to me via our OVH admin gui. I'd need to explicitly inform a VM about the particular OVH virtual MAC assigned to it to handle traffic for a particularly assigned IP address. In my usual RHEL/CentOS environment, I'd define this mapping in my network config file

/etc/sysconfig/network-scripts/ifcfg-eth0

with the statement HWADDR=ab:cd:ef:gh:ij:9f.

With the help of this mapping statement... my network would work and my IP traffic would flow correctly.

Now in the new vRack environment... the OVH admin gui no longer generates virtual MAC ID's for any of my assigned IP's. This field is entirely blank.

I understood the OVH support guys to be telling me to now simply accept the Virtual MAC ID's issued by my XenServer hypervisor itself. If I attempted to use these self-generated MAC values in the earlier non vRack environment... OVH wouldn't recognize them and my traffic wouldn't route. Now I'm being advised to trust that these self generated MACs are going to route... and the OVH networks don't need to know about these values for my traffic to flow properly.

I'm having a challenge understanding how the OVH network/datacenter is going to know how to map this traffic without assigning me a specific MAC ID.

Not too surprising to me... I'm not able to get any IP traffic to flow in this odd "No OVH Virtual MACs" environment.

What am I missing here? Are the MACs that my own XenServer is generating on its own (apparently totally separate and independent from any OVH involvement) of any prospective value here? Should these independently created MACs actually have some potential to be useful in this new vRack environment?

I'm having a mental problem handling this transition to the vRack.

Can anyone help shine some light on this for me?