NAT Cloud in EVE-NG

NAT Cloud in EVE-NG

I want to share with you how to create a NAT cloud in the EVE-NG community edition. Essentially, this is a virtual network with a DHCP server, which will allow NAT connections over the management interface of the EVE-NG VM for Internet access.

Interface, DHCP Server and NAT

First of all, we need to create a network which can be used in the topology. I’ll be using the predefined pnet9 interface (Cloud 9 network) for this, but any other interface will do.

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ip address add 192.168.255.1/24 dev pnet9 echo 1 > /proc/sys/net/ipv4/ip_forward iptables -t nat -A POSTROUTING -o pnet0 -s 192.168.255.0/24 -j MASQUERADE

This will assign an IP address to the device, enable IP forwarding in the kernel and establish an iptables rule to NAT the traffic to the pnet0 interface, which has the management IP address assigned. Technically, the pnet devices are bridges, but for the sake of this note this does not matter.

DHCP Server

We need an DHCP server on this interface lest we have to configure all the IP addressing for the Internet connection manually.

1 2	# Install DHCP Server apt-get install isc-dhcp-server

Next, we need to modify the DHCP server configs to look as follows:

1	INTERFACES="pnet9"

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authoritative; # EVE-NG NAT Interface subnet 192.168.255.0 netmask 255.255.255.0 {         range 192.168.255.10 192.168.255.240;         interface pnet9;         default-lease-time 600;         max-lease-time 7200;         option domain-name "lab.your-domain.org";         option domain-name-servers 8.8.8.8;         option broadcast-address 192.168.255.255;         option subnet-mask 255.255.255.0;         option routers 192.168.255.1; }

Finally, start the DHCP server and enable it to start during boot

1 2	systemctl start isc-dhcp-server systemctl enable isc-dhcp-server

Thats about it. Whenever you use the Cloud 9 interface, there is a DHCP server running which allows Internet access.