FRRouting (FRR) is an open-source routing software suite that turns a Linux/Unix host (VM, container, bare metal) into a router by running standard routing protocols in user space.
Proxmox VE (PVE)
Prereqs on each PVE node (one-time)
# To use the SDN routing integration you need to install the frr-pythontools package on all nodes
apt update && apt install -y frr frr-pythontools
systemctl restart frr
systemctl status frr
# Then enable the frr service on all nodes
systemctl enable frr.service