Configure SDN NAT Internet Gateway Server - UpCloud
10 Jan 2022 #linux
In order to make this work, “source IP filtering” will need to be “disabled” on the private interface “SDN” gateway machine
1st Gateway machine:
Usefull packages:
apt update && apt install iptables net-tools
IP forwarding allows the VM to forward packets to target:
echo net.ipv4.ip_forward=1 >> /etc/sysctl.conf
sysctl -p
Find the networks private IP:
ip route
iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -o eth0 -j MASQUERADE
To persist these changes so that the NAT rule is automatically enabled when the VM:
apt install iptables-persistent
#iptables-save > /etc/iptables/rules.v4
2nd Configure Backend Machine:
Check gateway IP and add it to the VM routes:
ip route
ip route add 169.254.169.254 via 192.168.1.1 dev eth0;
ip route replace default via 192.168.1.2
Make persistent:
nano /etc/network/interface
auto eth0
iface eth0 inet static
address 192.168.1.3
gateway 192.168.1.2
.