Please see below:
# 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!
source /etc/network/interfaces.d/*
auto lo
iface lo inet loopback
iface lo inet6 loopback
auto enp5s0
iface enp5s0 inet manual
up ip route add -net 37.27.96.129 netmask 255.255.255.192 gw 37.27.96.129 vmbr0
up sysctl -w net.ipv4.ip_forward=1
up sysctl -w net.ipv4.conf.enp5s0.send_redirects=0
up sysctl -w net.ipv6.conf.all.forwarding=1
up ip route add 65.21.172.169 dev enp5s0
up ip route add 65.21.172.170 dev enp5s0
up ip route add 65.21.172.171 dev enp5s0
up ip route add 65.21.172.172 dev enp5s0
up ip route add 65.21.172.173 dev enp5s0
up ip route add 65.21.172.174 dev enp5s0
up ip route add 192.168.0.0/16 via 37.27.96.174 dev vmbr0
up ip route add 172.16.0.0/12 via 37.27.96.174 dev vmbr0
up ip route add 10.0.0.0/8 via 37.27.96.174 dev vmbr0
auto vmbr0
iface vmbr0 inet static
address 37.27.96.174/26
gateway 37.27.96.129
bridge-ports enp5s0
bridge-stp off
bridge-fd 0
pointopoint 37.27.96.129
#Main IP configuration
auto vmbr1
iface vmbr1 inet static
address 65.21.172.169/26
bridge-ports none
bridge-stp off
bridge-fd 0
hwaddress ether
#WAN 1
auto vmbr100
iface vmbr100 inet manual
bridge-ports none
bridge-stp off
bridge-fd 0
#LAN 100
auto vmbr2
iface vmbr2 inet static
address 65.21.172.170/26
bridge-ports none
bridge-stp off
bridge-fd 0
hwaddress ether
#WAN 2
auto vmbr200
iface vmbr200 inet manual
bridge-ports none
bridge-stp off
bridge-fd 0
#LAN 200
auto vmbr3
iface vmbr3 inet static
address 65.21.172.171/26
bridge-ports none
bridge-stp off
bridge-fd 0
hwaddress ether
#WAN 3
auto vmbr300
iface vmbr300 inet manual
bridge-ports none
bridge-stp off
bridge-fd 0
#LAN 300
auto vmbr4
iface vmbr4 inet static
address 65.21.172.172/26
bridge-ports none
bridge-stp off
bridge-fd 0
hwaddress ether
#WAN 4
auto vmbr400
iface vmbr400 inet manual
bridge-ports none
bridge-stp off
bridge-fd 0
#LAN 400
auto vmbr5
iface vmbr5 inet static
address 65.21.172.173/26
bridge-ports none
bridge-stp off
bridge-fd 0
hwaddress ether
#WAN 5
auto vmbr500
iface vmbr500 inet manual
bridge-ports none
bridge-stp off
bridge-fd 0
#LAN 500
auto vmbr6
iface vmbr6 inet static
address 65.21.172.174/26
bridge-ports none
bridge-stp off
bridge-fd 0
hwaddress ether
#WAN 6
auto vmbr600
iface vmbr600 inet manual
bridge-ports none
bridge-stp off
bridge-fd 0
#LAN 600
I have used this setup script for the network:
https://github.com/la-cc/hetzner-proxmox-single/blob/main/script/network_config_updated.sh as I couldn't get it working myself either
