Is there any example of how to set up a NAT network

Community Support Network
1

Hi guys,
i follow the document and successful set up a bridge network, but i don’t know how to set up a NAT network. there is only a few topic about NAT network and the document is confusing for me. so i want to follow a NAT network example so i can follow it and solve this problem.
Thanks!

2

OpenNebula doesn’t perform NATing, you have to do so on your own while setting up the bridge. OpenNebula will only create the bridge automatically if it doesn’t exist when a VM requests a bridge port.

3

Hi,

I can share my existing setup reference as a example

Environment:
Host OS: UBUNTU 22.04
Opennebula Version: 6.6

KVM Host Setup (Follow Official Documents: KVM Node Deployment — OpenNebula 6.6.0 documentation

NAT Network Setup

Install DNSMasq

sudo su -c “apt -y install dnsmasq dnsmasq-base”

systemctl stop dnsmasq && systemctl status dnsmasq --no-pager

echo ‘[NetDev]
Name=nat-br0-nic
Kind=bridge’ > /etc/systemd/network/cloudbr0-nic.netdev

echo ‘network:
version: 2
renderer: networkd
ethernets:
nat-br0-nic: {}
bridges:
nat-br0:
addresses: [ 172.16.0.1/24 ]
interfaces: [ nat-br0-nic ]’ > /etc/netplan/cloudbr0.yaml

sudo netplan --debug generate && sudo systemctl restart systemd-networkd

echo ‘interface=nat-br0,lo
bind-interfaces’ > /etc/dnsmasq.conf

systemctl start dnsmasq && systemctl enable dnsmasq && systemctl status dnsmasq --no-pager

iptables -t nat -A POSTROUTING -s 172.16.0.0/24 ! -d 172.16.0.0/24 -j MASQUERADE

sudo sh -c “iptables-save > /etc/iptables.rules”

sudo sh -c “iptables-restore < /etc/iptables.rules”

netfilter-persistent save
iptables -t nat -L -n -v

Now Configure Network on Frontend

cat > vnet0.txt <<EOF
BRIDGE = “nat-br0”
BRIDGE_TYPE = “linux”
DESCRIPTION = “NAT Default Network”
DNS = “172.16.0.1 8.8.8.8 1.1.1.1”
GATEWAY = “172.16.0.1”
NETWORK_ADDRESS = “172.16.0.0”
NETWORK_MASK = “255.255.255.0”
OUTER_VLAN_ID = “”
PHYDEV = “”
SECURITY_GROUPS = “0”
VLAN_ID = “”
VN_MAD = “fw”
AR=[
TYPE = “IP4”,
IP = “172.16.0.2”,
SIZE = “250”
]
EOF

Hope this will help, Good Luck.

4

hey
While setting Up NAT in physical resources it works via vmware or vcenter might work.

5

hi simhaonline

NAT Network Setup is KVM node or vm intance.
u can share with me?

6

On KVM Node