[SOLVED] Basic question regarding OVH's failover IPs

Datacenter1

Member
Apr 3, 2018
4
0
21
56
Hi

Sorry for the newbie question...

If I set a Proxmox Cluster in OVH with each vm using failover IPs it means I can migrate from/to any node without changing the device assigned to the FO IP from OVH management panel? or do i have to update the device in ovh's panel each time i migrate a vm to another node?

Thank You
 

zorrobiwan

Member
Jun 10, 2020
24
3
8
49
Hello. You can certainly move the FO IP from one host to the other manually using the OVH manager. That's how I work since years.

I've read it's possible to make this automatic using the OVH API and/or using Ripe IP range and using a script to send some arp packages. But I've never investigate that way.
 

Datacenter1

Member
Apr 3, 2018
4
0
21
56
Thank You,

I already using vRack but just for the cluster and backups but @spirit suggestion makes sense and worth the try

Another way would be calling the OVH APl + Proxmox Hookscripts but I feel this is way beyond my coding skill :(

Another mistake I did with OVH was to order IP's in blocks (/29), is better to order /32 because FO IP can be only moved in ranges and is the same price per IP no matter the block size. Hopefully this will help others.
 

zorrobiwan

Member
Jun 10, 2020
24
3
8
49
Yes I order them always /32 for the same reason.

But am I wrong, but it seems we can only associate IPs range to the vrack, not individual /32 IPs ?
 

zorrobiwan

Member
Jun 10, 2020
24
3
8
49
Here is something interesting
https://community.ovh.com/t/cluster-proxmox-ip-dediee-a-chaque-vm/11621/8

Translated interesting §:
If you want to do automatic failover between several servers / vm, the most flexible solution remains the vrack.
You have to order a complete ripe block and add it to the vrack associated with your servers. You put your machines in place, the mac addresses are not to be configured in this case, the arp tables directly take the macs that you put on your vm.
Once the failover ip is configured, be careful to use the last ip of your block as a gateway,
For the switch to take place, traffic must be generated from the new location. This will update the arp tables, so your switch between servers can be easily automated.

To be tested
 
  • Like
Reactions: Datacenter1

zorrobiwan

Member
Jun 10, 2020
24
3
8
49
Tested and it works very well !

I had to change the configuration of my vmbr1 bridge on the host and be careful as we can't have 2 different gateways in the same time on a container

will write a blog post about this and will referenced it here later

In brief:
- need an IPs range (not individual IP /32) linked to the vrack
- need a bridge configured on the vrack interface on the host
- configure an IP from the range (not the first one, neither the two last one from the range) without MAC, using the correct bridge and with the correct gateway (which is the one before the last one from the range)
 
  • Like
Reactions: Datacenter1

Datacenter1

Member
Apr 3, 2018
4
0
21
56
Tested and it works very well !

I had to change the configuration of my vmbr1 bridge on the host and be careful as we can't have 2 different gateways in the same time on a container

will write a blog post about this and will referenced it here later

In brief:
- need an IPs range (not individual IP /32) linked to the vrack
- need a bridge configured on the vrack interface on the host
- configure an IP from the range (not the first one, neither the two last one from the range) without MAC, using the correct bridge and with the correct gateway (which is the one before the last one from the range)
Are your servers located in the same datacenter or country? I guess this won't work for servers in different countries and/or regions (RIPE/ARIN)
 

About

The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get your own in 60 seconds.

Buy now!