Mastering Proxmox - Third Edition

Adding NAT/masquerading

NAT is a way to hide internal network IP addresses from the external network, such as the internet. Any outgoing traffic uses the main host IP address instead of using its own local IP address. Add the last three lines of the following post-up and post-down settings to the /etc/network/interfaces configuration file. Only add these lines under the virtual bridge configuration that needs the NAT option:

auto vmbr0 
iface vmbr0 inet static 
address 192.168.145.1 
netmask 255.255.255.0 
    bridge_ports none 
    bridge_stp off 
    bridge_fd 0     post-up echo 1 > /proc/sys/net/ipv4/ip_forward 
    post-up iptables -t nat -A POSTROUTING -s '192.168.145.0/24' -o eth0    -j MASQUERADE post-down iptables -t nat -D POSTROUTING -s '192.168.145.0/24' -o ...