How does HA networking work?

[drjaymz@]

The scenario is that I have a NAT on node 1 using 192.168.1.64/24 thats because the VM's I imported to it are expecting a gateway of 64. That all works perfectly well.
I then set up nodes 2 and 3 but not the NAT because I obviously can only have a single gateway of 64. So if I break my first node the VMs duly boot up but how do I get that networking working, I am assuming that I somehow have to have the same config on each node.

Its a bit contrived because being a proof of concept all 3 proxmox nodes are themselves nested VM's and to work all three subnets would have to be able to route to each other.
I suppose that if they were baremetal then we'd just be passing the VM's directly down to the same external gateway and that would be fine.


You know what? I just read that and although I know what I mean it probably doesn't make any sense outside my head so have a go anyway and I'll answer any questions until we work out what the question is!

 

[Pifouney]

Your funny guy ! x'D

Retake the bases of a physical network.

Yes, you can have only one gateway by hosts, but you can use as many as you want of network in the same cable.
For your test, i'll presume you want to try the HA on proxmox.

You need to enderstand a simple unique concept: All need to be replicated:
yours switch, yours networks cards, etc etc

If you want to do HA, you need to configure networks by usage, not like you want. On alls hosts:
1 network HA keepalive dedicated
1 network for yours VM
But, the HA network doesn't need internet connectivity. You can use it without any GW.
Idealy, 1 network dedicated for migrating VM/services between nodes.

Idk the configuration of your Host for this test, but use containers without nesting in you test environnement, for reducing latences and connectivity issues.
Try this with services that doesn't write or over use CPU/RAM, in nesting configurations you can see problem from everywhere in this kind of tests

Bests regards