diff --git a/scripts/compute-ext-net.sh b/scripts/compute-ext-net.sh
new file mode 100755
index 0000000..ead559c
--- /dev/null
+++ b/scripts/compute-ext-net.sh
@@ -0,0 +1,11 @@
+#!/bin/sh
+
+apt-get update
+apt-get install bridge-utils
+brctl addbr databr
+ifconfig databr 192.168.0.254/24 up
+ip link add type veth
+ifconfig veth0 up
+ifconfig veth1 up
+brctl addif databr veth0
+iptables -t nat -A POSTROUTING -s 192.168.0.0/24 \! -d 192.168.0.0/24 -j MASQUERADE