Hurricane Electric (http://he.net) provides a free IPv6 “6in4” tunnel that works well with CeroWrt. This gives your router a globally routable IPv6 address so that you can directly connect to other IPv6 resources on the Internet. It’s straightforward to do this: first you create a free tunnel account through Hurricane Electric’s Tunnelbroker site (http://tunnelbroker.net) and then configure your CeroWrt router.
The Sample Script for IPv6 tunnel makes it easy to set up the tunnel once you have created your Tunnelbroker account. This procedure has been tested with the Modena 3.7.5-2 and newer builds.
NB: As of March 2013 (CeroWrt 3.7.5-2), the automatic re-establishment code of the 6in4 module appears not to be working. You will need to re-establish the tunnel manually (see Step 3 below) when your external IP address changes. Bug is being tracked here: #358
1. Create an IPv6 6in4 tunnel
* Your Tunnel ID and its creation date.
* A text field where you can fill in a human-readable name for the tunnel
* The IPv6 Tunnel endpoints: both an IPv4 and IPv6 address for the server (far) endpoint, and the IPv4 & IPv6 address for your end of the tunnel.
* DNS resolver addresses (IPv4 & IPv6)
* Routed IPv6 prefixes for a /64 (single network) or /48 address.
* rDNS name servers for this block of addresses.
You have now created the tunnel. (The Tunnel Broker home page lists all the tunnels that you have established.) Hurricane Electric is listening on their end, waiting to pass IPv6 traffic to and from your external address listed above. Now you need to configure the CeroWrt router to use the tunnel.
2. Configure CeroWrt to use the IPv6 Tunnel
3. Manually re-establish the tunnel when your IPv4 address changes
If you do not have a static IPv4 address for the client end of the tunnel (perhaps you have a DSL or cable modem connection), your tunnel will go down each time your external IPv4 address changes.
The Tunnel Broker has a facility for re-registering your current client IPv4 address. The page at https://ipv4.tunnelbroker.net/ipv4_end.php has details. As a quick fix, you can visit the URL below to inform the Tunnel Broker to update your TUNNELID to autodetect your IPv4 address:
or use the non-HTTPS URL described in the script below. If the update goes properly, you see a response similar to this:
+OK: Tunnel endpoint updated to: 188.8.131.52
The tunnelbroker.sh script sets up a tunnel using the configuration
parameters provided by the Hurricane Electric Tunnelbroker.net site. As
of CeroWrt 3.10.50-1, this script is pre-installed in
The script is also available as part of the CeroWrtScripts bundle on GitHub: https://github.com/richb-hanover/CeroWrtScripts/blob/master/tunnelbroker.sh
Update: On 17Nov2014, the CeroWrtScripts on github were updated to fix a problem with supplying the correct username. Read the tunnelbroker.sh script for more details. The version of the pre-installed script in CeroWrt 3.10.50-1 does not contain this fix: edit the file manually to use the correct username - your plain UserID.
The screenshots below illustrate the process of setting up a TunnelBroker account at HurricaneElectric.net
Figure 1: Main Page, showing Create Regular Tunnel link
Figure 2: Create New Tunnel page
Figure 3: Tunnel Details page
Figure 4: Configuration script for CeroWrt and OpenWrt
Figure 5: Advanced Settings