I do love it when I spend an entire evening, into the wee small hours, learning a lesson I already knew.
Tonight I've been schooled. Badly. As per the post title, the devil really is in the details.
What devil, and what details, I hear you not asking.
Well, in a nutshell, I've spent the last couple of weeks struggling with a slow connection to the Internests. around 1.5 to 2 megabit/second. I finally thought to run a speed test from my laptop, and that was showing the expected 7 megabits/second. Realising that this slowness began when I build my new computer, I put two and two together and came up with five.
My first step towards having a fully shaven yak was reading about some potential IPv6 problems, so I tried to disable IPv6 in my Ubuntu 9.04. This is not so easy, as IPv6 is now compiled into the kernel, rather than being a module. Long story short, I ended up compiling my own version of the kernel with IPv6 removed. This made no difference
My next trick was to start playing with the MTU size, which appeared to make a little bit of difference, but 2.5 megabit/second was still a long way short of what the laptop was getting. After a lot of tarting around with different MTUs, and other interesting ;) networking settings, I was getting desperate. I was wondering if I had plugged the homeplug adapter into a surge protected socket by mistake.
I hadn't, but I for some reason decided to pull out the homeplug and check that the network cables were secure. Plugged it back in, ran a speed test, and good morning proper speeds. Whether the homeplug wasn't plugged in fully before, or whether it had crashed (for the first time in a couple of years) I will probably never know.
What I do know, is that after almost 5 hours of recompiling, downloading, searching, and tweaking, a 5 second "have you tried turning it off and on again" did the trick.