Monthly Archives: September 2013

TV licensing are misleading and threatening

I got a letter this morning:


This made me angry for a number of reasons.

I have not received any previous letters, so either they’re lying to me or such letters got lost in the post.

It adopts a threatening tone and starts out making it sound as though they’re taking me to court. Given that my old housemate moved out last month and took the only television in the house with him (and we don’t record or watch live TV on any other device), this strikes me as aggressive and completely without foundation.

I phoned them all ready to give a human being a piece of my mind. After navigating through four levels of menu system, a polite voice told me all their operators were busy and hung up on me.

I was quite tempted to ignore it and see what they do next, but for now I’ve given in and visited their website to declare I don’t need a licence. They tell me that they ‘may follow this up with a visit’. They can try, but since their inspectors have no legal right to enter my property or question me, it won’t go well for them.

This kind of behaviour is exactly why we should scrap TV licensing and make the BBC compete on the open market like every other TV station. The letter merely upset me, but its effect on a more vulnerable or less well informed member of society could have been a lot worse.

Sysadmin by point and click

I promised an update on Google Apps some time ago. This week, we finally flipped the e-mail for Saint Columba’s over to Google Apps hosted mail. Combined with using Mythic’s DNS servers (free with the domain registration and with a pretty nice web interface), that meant the church’s online presence was fully disentangled from my servers for the first time in years.

While that’s a good thing on a pragmatic, I-don’t-have-time-to-run-this-any-more basis, it’s been a bit of a rough ride. Here are some of the things I’ve learned.

  • Google apps ‘groups’ are a replacement for what you think of as e-mail aliases or forwarders. Make a group, set it to ‘anyone on the internet can post’, and add the addresses you want it to forward to. In my case, I found Google Apps e-mail users which were part of the group failed to get any messages sent to it. Then it suddenly started working after 24 hours. The frustration of not knowing why this is (or if it’ll stop working again tomorrow) was probably the low point of the whole exercise.
  • Forwarding mail from a google account somewhere else requires somewhere else to give you a confirmation code before it’ll work. Not entirely unreasonable, but frustrating when it’s two accounts in the same Apps domain.
  • The out of office auto-responders on external GMail accounts don’t work for mail forwarded via apps groups/aliases. There is no documentation of this, they just fail to send a reply (not really an Apps problem, more a migration from old GMail account to Apps problem).
  • Single-line or empty test messages with just a subject line will often get eaten/filtered to junk by Google Apps as spam. This makes testing rather ‘fun’.
  • Google Apps e-mail supports two-stage authentication with your phone, which is handy, but domain administrators have to flip a setting to let users enable it. Whilst you’re there, enable SSL everywhere (boo for this not being the default).
  • All parts of Google Apps have IPv6 enabled. Nice to know we can remain the only (?) church in Oxford with an IPv6 website and e-mail.

Now it’s done and working, we’ll be sticking with it, but I can’t pretend it’s been very good for my blood pressure getting there.

APT and HTTP redirects

Recently, I was issued with a rather nice Thinkpad X230 for my new work laptop. Not being a huge fan of Windows 8, I decided to go for Debian as my operating system. And this presented me with a problem: my company has a local mirror of the Debian archive which I’d like to use in my /etc/apt/sources.list, as when I’m at the office, I have a fast network connection to it. But if I configure things that way, I’m out of luck outside the office if I want to install or update packages, as the private mirror isn’t visible to other networks.

Inspired by the Raspberry Pi’s mirror director (which takes advantage of the way APT follows HTTP redirects), I put together a solution to redirect me to the right mirror depending on where I am (based on a fairly naive reverse DNS lookup). Note that when you don’t have a private mirror around, you can use to apply the same redirection trick to point you at a nearby mirror based on geolocation of your IP address, etc.

It’s been running for a couple of weeks for my laptop’s use and seems to work. The only disappointment is that apt-get doesn’t print out the redirect chain, so you have to take it on faith that you really have been directed to the right place (of course, you can get a good idea of that by hitting up the redirector URL in a browser).

See Bitbucket for the code and deployment instructions. Let me know if you’re using it!

Twin Nvidia graphics cards and Ubuntu

My home desktop PC, running Ubuntu, has had two monitors for quite some time, but when an obliging friend on IRC offered me a third, I couldn’t pass it up.

This meant installing a second graphics card, and fortunately I had a second Nvidia GeForce 9400GT (PCI Express), identical to the one already fitted. This went in perfectly but wasn’t recognised by anything. When I took the cover off again and looked more closely, it seems there’s a jumper which needs rotating to switch into ‘dual video cards’ mode:





Having done this, everything sprang into life. Tell Nvidia’s settings applet to overwrite the existing Xorg.conf file (not merge with it), set them all as separate X displays, and Ubuntu spreads cleanly across three of them. Shame I don’t have a fourth…

Words to live by

“Read the error message” – Me

“It’s always simpler than you think” – Me

“If a job’s worth doing, it’s worth doing properly” – my grandfather.

Why am I going all philosophical on you? Well, I wasted far too much time last night on a networking problem, and as with 99% of the technical issues I run into, all of the above applied.

The problem was apparently straightforward: I powered down and disconnected my home ‘server’ which had been creaking away in a corner quite happily. It connected to my home network via a powerline ethernet adapter, and had a static IP address.

Later on, after my new internet connection had been installed, with consequent change of router, I plugged it all back in and couldn’t ping the server. I checked the cable. I checked the power-over-ethernet thing. I theorized (wrongly) that Sky’s router wouldn’t talk to statically configured clients it hadn’t handed a DHCP lease to. I drafted in Michael with some switches and tcpdump, and he established that no packets were emerging from my machine. A couple of commands later, we came to the conclusion that the network port didn’t think it had a cable plugged into it.

At this point, I had a lightbulb moment and sheepishly admitted that this machine’s onboard networking had died a year ago and I’d put in a new Ethernet port on a PCI card. Sure enough, moving the cable to the right network port made everything spring into life.

Assumption is, and always will be, the mother of all screw-ups.

I’ve ensured this won’t happen again by taping up the dodgy port, as I ought to have done a year ago: