Background

I just finished doing a networking reconfiguration and needed to change the IP addresses of my three Proxmox nodes.

Overall, the process is simple albeit a bit cumbersome.

1. Access the node you want to update

I did this by plugging my monitor directly into the HDMI or DisplayPort ports on the physical machines in order to bring up the Proxmox shell. Then logged in as the root user.

2. Update the /etc/network/interfaces file

Run the following command to open the file in vi

vi /etc/network/interfaces

The file will look something like this:

# network interface settings; autogenerated
# Please do NOT modify this file directly, unless you know what
# you're doing.
#
# If you want to manage parts of the network configuration manually,
# please utilize the 'source' or 'source-directory' directives to do
# so.
# PVE will preserve these directives, but will NOT read its network
# configuration from sourced files, so do not attempt to move any of
# the PVE managed interfaces into external files!

auto lo
iface lo inet loopback

iface enp3s0 inet manual

iface enp4s0 inet manual

iface enx0c3796484df7 inet manual
#usb-ethernet

auto vmbr0
iface vmbr0 inet static
        address 10.0.0.106/24
        gateway 10.0.0.1
        bridge-ports enx0c3796484df7
        bridge-stp off
        bridge-fd 0

auto vmbr1
iface vmbr1 inet manual
        bridge-ports enp3s0
        bridge-stp off
        bridge-fd 0
        bridge-vlan-aware yes
        bridge-vids 2-4094

auto vmbr2
iface vmbr2 inet manual
        bridge-ports enp4s0
        bridge-stp off
        bridge-fd 0
        bridge-vlan-aware yes
        bridge-vids 2-4094

source /etc/network/interfaces.d/*

This file contains the definitions of all of the network interfaces on the node. I needed to update the address and gateway of the interface vmbr0. This is the interface through which I can access the Proxmox GUI.

I gave the node an address that wasn't already being used and set the gateway to the IP address of my router / firewall.

3. Update the /etc/hosts file

Update the IP address entry in the /etc/hosts file