Setup Network bridge
Before setting up any VMs in our cluster, you will need to set up a network bridge, this may be a bit confusing for some, but I hope this all makes sense.
NOTE: These steps must be performed on each node of the cluster, or else High Availability won't work!
For some reason that I can't entirely fathom, Proxmox doesn't install all the tools it needs to perform network configuration. so before we go any further, we need to fix that.
Open the shell and issue the following command
apt install ifupdown2
4. On each node of your cluster, follow these steps. first select the node, in this case, "Prox1" then select “network”
5. You will see the network interface we set the static IP address for when we first started setting up Debian. We now need to remove the IP address from the NIC and add a bridge which will carry the IP address.
6. Select the NIC, in this case, “enp0s25” and then select edit
7. Copy the name of the interface into the paste buffer and then delete the IP address and gateway. The network configuration should look similar to the following
8. Now select “Create” from the drop-down menu above the NIC name and select “Linux Bridge”
9. In the IP address, add the IP address you had originally set in the NIC; in this case its 10.110.10.5/24 with the gateway, which in this case is 10.110.10.1 now in the “Bridge ports” paste in the name of the NIC, in this case, “enp0s25.”
10. Once completed hit "Apply Configuration"
11. REPEAT ON EACH NODE!