Hurricane Electric IPv6, m0n0wall, and Dynamic IPs

After years of wanting it, I finally got around to setting up an IPv6 tunnel. (My brothers’ Flash plugins weren’t too pleased for some reason, but I’ll re-enable IPv6 on their machines later)

I quickly discovered that there was one small problem though. Hurricane Electric’s TunnelBroker.net doesn’t offer a DynDNS-style API for DNS-O-Matic to replicate my m0n0wall DynDNS updates to.

They do provide a more homegrown HTTP API and I tried e-mailing DNS-O-Matic to see if the could add support for it, but got no response and, since m0n0wall doesn’t let you hook on-reconnect events, I needed something ddclient-like.

I checked around to see if anyone else had m0n0wall-based solutions, but found nothing and, being the geek I am, I felt more like whipping up a custom tool in an afternoon than spending an hour trying to puzzle out the search keywords for a more flexible ddclient-alike.

upd_ipv6.py requires Python 2.5 (I think) and LXML (m0n0wall’s interfaces status page isn’t well-formed enough for ElementTree and I didn’t feel like doing any SAX-style parsing by hand). It’ll probably work on Windows and MacOS, but I’ve only tested it on Linux and it’s not a daemon, but that’s what cron and the Windows task scheduler are for.

To configure it, run ./upd_ipv6.py --dump-config and then edit the config file at the path it mentions. You’ll probably want to create a custom m0n0wall user that can only access the Status > Interfaces page.

Once that’s done, just stick it somewhere out-of-the-way, add a cron line like this to run it once every five minutes:

*/5     *       *       *       *       ~/bin/upd_ipv6.py

It’ll only contact TunnelBroker.net if your IP changes.

Hurricane Electric IPv6, m0n0wall, and Dynamic IPs by Stephan Sokolow is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.