diff --git a/tools/setup-nat-ubuntu b/tools/setup-nat-ubuntu
new file mode 100755
index 000000000..8e9d8fe3d
--- /dev/null
+++ b/tools/setup-nat-ubuntu
@@ -0,0 +1,14 @@
+#!/bin/sh
+
+# Run this script as root ("sudo ./setup-nat-ubuntu"). It has been tested on Ubunru 8.04.
+
+/sbin/iptables --table nat --append POSTROUTING --out-interface eth0 -j MASQUERADE
+/sbin/iptables --append FORWARD --in-interface tun0 -j ACCEPT
+
+/sbin/sysctl -w net.ipv4.conf.default.forwarding=1
+/sbin/sysctl -w net.ipv4.conf.all.forwarding=1
+
+/sbin/sysctl -w net.ipv4.ip_forward=1
+
+echo 1 > /proc/sys/net/ipv4/ip_forward
+