birds like wires

Dead Simple Dynamic DNS Updater

I’d been messing with ddclient, trying to get things to play nicely with DNS-O-Matic, Tunnelbroker and Hurricane Electric’s own dynamic DNS system. Problem was, although everything was configured correctly it still wouldn’t update my DNS! It worked when I told it to, but when the IP genuinely changed, it all went wrong.

It turns out that when my IP changed, ddclient was indeed trying to update things. However, it was trying to do it over the IPv6 tunnel which, due to the altered IP address, was now broken. And I could find no way in the config to specify that the tunnel should be updated first, over IPv4. Hmm.

So, I sacked off ddclient and went for the world’s simplest dynamic DNS client. A bash script and curl.

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Tunnelbroker and Dynamic IPs

http://www.flickr.com/photos/iandavid/4271317457/
Change of plan! While the details provided here are accurate and may well be useful if you’re configuring ddclient, I found issues updating my DNS information this way. So I opted for something much simpler, which I’ve written up here.

My shiny new router, which I’m hoping to write a proper article about soon, supports IPv6 tunnelling. IPv6 is going to become increasingly important over the next decade, as we’re running out of IPv4 (the ones that look like 208.67.220.220) addresses to give to all of the devices out there. Internet service providers are going to need to pick up the pace of handing these out, but in the meantime for those that don’t (such as BT) there are tunnelling services.

An IPv6 tunnelling service does basically what it sounds like; shoves your IPv4 traffic through a tunnel so that it pops out of the other end with a valid IPv6 address. You can then access services that only use IPv6… okay, that’s not many right now, but hey – you’re future proof! There are a few different providers out there, but I use Tunnelbroker. If your router supports it, you can configure the entry point to the tunnel from the details Tunnelbroker provide and pow! You’re accessing IPv6 sites.

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Fix Postfix for Gmail on Snow Leopard

This is a quick and dirty method for getting Postfix (as built-in on Mac OS X v10.6) to send mail via Gmail.

My little home server is a tweaked Mac mini, but Snow Leopard is the last version of OS X that will work on it without even more hacking around (besides, it’s the best version of OS X Server, IMHO). I had a search around on the web and after combining a few different methods, came up with this to make it work.

Sort out Certificates

Google changed to using Equifax as their certificate signing authority some time ago, but Postfix doesn’t know about them. So, you need to add their certificate (and we’ll add Thawte at the same time, for good measure).

Start by creating a certificates directory:

sudo mkdir /etc/postfix/certs

Jump into it and create a file called Equifax_Secure_CA.pem, then copy the following into it:

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