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Showing posts from September, 2013

Fedora Linux with Multiple Monitors

Quite annoyingly, a default install of Fedora with XFCE on a laptop computer doesn't support multiple monitors properly.  If you plug an external screen in, the only option is to mirror the main screen (using the function keys, fn-F3 or some such), which is seldom what I want.  I prefer having a bigger desktop stretched over both screens.  Even though the two may not have the same resolution, I think that it is a better use of pixels. Old Fashioned Setup Sometimes the prehistorical command line works best.  The two screens can be configured with xrandr , but one has to remember to rerun xrandr before the external screen is unplugged, to exclude it (turn it off).  It can be made more convenient by hooking two scripts to a pair of hot keys, which would bring your laptop machine back into this century. First you need to do some sleuthing.  Simply run xrandr with no parameters: $ xrandr Screen 0: minimum 320 x 200, current 1366 x 1536, maximum 8192 x 8192 VGA-0 connected


The Church of Global Warming alarmists are getting really desperate.  They are now claiming with 95% certainty that human produced CO2 is causing catastrophic global warming and that it must be stopped at all costs, otherwise the sky will fall on our heads tomorrow.  Humanity needs to extinguish all organic power stations and go back to shivering in caves to prevent further warming... Warming, What Warming? Unfortunately for the alarmists, reality just flat out refuses to play ball and back them up.  For the past 15 years, despite us having emitted massively more organic gasses than ever before, the earth simply refused to warm up.  How many more years of contradicting data will it take to make the Church of Global Warming prophets admit that their computer models are maybe just a wee little bit off kilter?  Could it be that there are lots of green things out there that love to breathe CO2? Global Cooling Anyone over 50 is old enough to remember their predecessor, the Church of

ARP, the mystery protocol that makes a LAN work

Address Resolution Protocol Usually, ARP just works and most people are blissfully unaware of it, but once in a while, I run into a problem. ARP is the mystery protocol that makes a LAN work.  When a host wants to talk to another host on a LAN, it sends out a Who Has w.x.y.z message and gets an I Am reply. After that the system knows how to talk to each other using their MAC addresses and the LAN switch knows how to route the packets between the two hosts.  Fail Over of Servers This is all very nice when you are running an ordinary LAN, but the wheels tend to fall off when you run a system with redundancy and fail over. What happens in a fail over case, is that some devices will remember the old connection and will refuse to talk to the backup host, because while the backup host has the same IP address as the now defunct host, its MAC address is different. The entries in the ARP table can take a very long time to time out, more than 8 minutes in most Linux systems.

Negative Disclosure

Some security related web sites have started to proclaim that they have had ' 0 Police Information Requests ', or something to that effect.  This is intended as a ' dead man's switch '.  When they do get a police information request, they intend to remove that statement, not update it to 1. This won't work.  When they get a subpoena with an accompanying gag order and remove that statement, they can probably be charged with obstruction of justice and contempt of court and likely a few other things as well, so those statements will never be removed. If you were wondering, I haven't gotten any information requests either - anyone can simply get the information from Google and don't have to ask me!


The Analytical Engine Whenever I glance at my site statistics, the USA is at the top of list - no surprise there, but the second entry is always Ukraine.  Uhmmm, what, why Ukraine? Is Google Analytics really so incredibly bad, or is the FSB based in Ukraine maybe? More likely someone in Ukraine just loves my ramblings and sits and clicks the refresh button all day... Take Back the Intertubes Bruce Schneier wrote a column on taking back the internet I just like that picture of Senator Hatch's Intertubes...

Throwing an Eliptic Curve Ball

Defeatist Attitudes The hullabaloo around the pervasive NSA and GCHQ snooping is still ongoing.  Nevertheless, the common public is indifferent, since they don't understand it and feel that they cannot do anything about it anyway - defeatism at its worst. Computer security is an asymmetric battle.  The little guy is up against goliath, with only some obscure mathematics to safeguard him. The sad fact of the matter is that we were never supposed to have to take on the likes of the NSA and GCHQ.  They were supposed to be the good guys, but their overreach have moved them over to the Dark Side. Leaky Sieves The problem is that the NSA and GCHQ are leaky sieves.  They gather tons of data and then leak it out to all and sundry - after all, what is the point of gathering data if nobody will ever look at it?  Therefore the only way to secure your data is to ensure that they can never get their grubby paws on  it in the first place. The computer geeks of the world have a heavy bu