Cluster Two Proxmox Servers with VLANs Across Different Subnets

[royzer]

Hello there, people!

Is it possible to create a Proxmox cluster using VLANs when the servers are on different subnets? Here’s my setup:

Main Server:
- IP Subnet: 192.168.1.x
- Runs behind a router (192.168.1.1)
- Has 2 NICs available

New Server:
- IP Subnet: 192.168.101.x
- Runs behind an OPNsense network (192.168.101.1), which is hosted by the main server
- Has only 1 NIC

Issue:
- The new server can ping the main server.
- The main server cannot ping the new server.

Is there a way to solve this and cluster the two servers using VLANs or any other method?

Thanks in advance!

 

[UdoB]

- Runs behind an OPNsense network (192.168.101.1), which is hosted by the main server

That's not good. When the main server fails this server has no connectivity?

- The main server cannot ping the new server.

That's not good.

You need guaranteed reachability for ssh+corosync (UDP ports 5405-5412) from each node to each other. And ICMP is too valuable for debugging to be disabled!

The limiting factor is the response time, not routing. It can only be a very few milliseconds. Also: https://pve.proxmox.com/pve-docs/pve-admin-guide.html#_requirements


PS: you know you need a third device for a stable cluster? Search for "Quorum-Device". https://pve.proxmox.com/pve-docs/pve-admin-guide.html#_quorum

 

[royzer]

My primary goal is to expand my existing system, as it's an older setup with limited options. After learning about clustering, I realized I could integrate a new system by clustering them together. Ideally, I want my VMs and containers to utilize the networking subnets managed by OPNsense. If it's possible to share OPNsense's subnet configuration across clustered devices, I’m all in. I can connect both systems to the same router and ensure the VMs and containers seamlessly operate within OPNsense's subnet structure.