Landis Vinchattle An aggregation.

September 13, 2011

Zone Firewall Taxonomy

Filed under: Security — Tags: — Landis V @ 9:01 pm

I’ve been thinking for some months (years, maybe) about how to properly implement a zone taxonomy/hierarchy for a global policy security configuration.  Perhaps because I’ve never really had the time to sit down and focus on the problem, it has always proven elusive.  I can see what I want to accomplish, but it requires just a little more thought than I’ve been able to devote to it.  Which is unfortunate.  I think this taxonomy/hierarchy combination could greatly simplify some of what I do.

Recently I’ve had an opportunity (scantily disguised as a shitload of work and frustration) to focus on this, think it through, and see if it actually has the potential to prove beneficial.  That’s what I’ve spent this afternoon doing, and it’s time to start making some notes on my thoughts and analyzing the conclusions therefrom to see if this is actually a workable idea or if it’s something that’s been nagging at me for years with no viable solution, or at least none that I can see clear.

For the reader, I’m writing this primarily to clarify and focus my own thought process, so I won’t go into any detail on concepts that are already clear in my mind.  I will define all zones with the prefix “Zone” to describe the type of element it is (since there are many possible elements in networking – lists, subnets, zones, services, etc.).  From there, I will append consecutively more specific elements to describe the particular zone.  This yields a few questions, and a few things that will require further thought.  I will immediately note the ones that come to mind to prevent their loss as my mind wanders.

Question:  Should zones become so specific as to be itemized down to a specific host, or even a specific service?

Implementation Thought:  Zone permissions should be configured in a top-down list from the most granular to the most generic.  This is in line with traditional list-based access control methodologies.

May 1, 2011

Washing machines, and what’s missing

Filed under: Hacks,Home — Tags: — Landis V @ 1:43 pm

My washing machine recently overflowed.  I thought I’d located and repaired the source of the problem by JB Weld’ing a hole in the inlet valve incurred from washing a very large comforter (that’s another story), but that does not appear to have been the case, as the JB Weld held and we had another large puddle today.  That started me not only tearing apart the machine again, but considering all the things that have been left out of a modern washing machine to prevent this very kind of problem.  This particular machine was purchased somewhere around 2003, so perhaps things have changed since then.

After disassembling the machine and finding no obvious leak sources, I came to the conclusion that the water level sensor must be experiencing intermittent problems.  Testing with a multimeter per the instructions at http://www.acmehowto.com/howto/appliance/washer/check/waterlevel.php would indicate that the switch is good, but a little further playing around (testing, whatever you like to call it) may have provided clues to the intermittent nature of the problem.  Blowing into the pressure port on the switch generally triggers the audible “click” and corresponding resistance change between terminals of the switch.  However, I discovered by repeatedly blowing into the pressure port that the switch seems to intermittently stick and not click over.  Even this isn’t quite consistent with the behavior we experience with the machine, as it does seem to eventually kick over to the next cycle, but it’s enough in line that I believe it’s probably the source of the problem.  I could replace the switch – which I will – and the problem would be solved.  For another seven (Two? Ten? Who knows!) years, and then I’m back to teardown and trace again.

Whether or not I get around to it remains to be seen, but there were a couple of ideas that came to mind as a result of the leak.  First off, at the very least, the machine should have a water sensor that would trigger shutdown of the system upon detection of water.  From the factory, this should be simple and basic, and I would not expect it to require more than $10.00 – 15.00 in parts, as I think I can buy the needed parts as a consumer at that price.  Second, and more advanced, it should be possible to create a straightforward state diagram that would allow even greater control of the behaviors of the machine.  I’ll flesh out my idea on a kill switch first, since that should be pretty straightforward, and then if I have time I’ll proceed with thoughts on the state diagram and what would be required.

What’s required

  • Water sensor, such as this one (I purchased one of these from Amazon in ’09; fortunately, it’s never needed to go off).

Note:  This is another one of those posts that I started once upon a time and never got back to finishing, but the good news is that I was able to fix the problem very simply, and it wasn’t a problem with the switch.  There’s a small box down low on the tub at the other end of the tube running to the switch.  One of the techs at the local appliance repair store suggested pulling the tube off at that end, and that I would likely find some gunk plugging it.  He was absolutely correct, and digging it out with a toothpick/blowing through the tube from the top end bought me another good year of functionality without a problem.  And the next time it overflowed?  Same problem, same fix.  Haven’t ever gotten around to the kill switch sensor, but we did leave the water sensor on the floor next to it and it has helped a couple of times.

April 22, 2011

4/22

http://yro.slashdot.org/story/11/04/22/165217/How-People-Broadcast-Their-Locations-Without-Meaning-To?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Slashdot%2Fslashdot+%28Slashdot%29&utm_content=Google+Feedfetcher

Companies are like evolving living organisms.  Think of the dotcoms – they are the genetic offspring of business and the internet – two different families in the genetic hierarchy of “things”. They areimpacted by their environment (which businesses and the Internet are also kind of a part of… maybe not entirely unlike nature/nurture), but also by microorganisms like employees.  Employees certainly represent the cells and systems of the business organism, but also viruses that impact the development of the organism.  That may lead to the collapse (“extinction”?) of certain types of, or even individual businesses, as viral organisms overtake them and make them unfit for survival in their environment.  Interesting train of thought, could easily develop into an entire post of its own.

http://forum.xda-developers.com/showthread.php?t=1037918 and to a lesser/secondary extent http://forum.xda-developers.com/showthread.php?t=1041077 Fascinate ROMs on Mesmerize.  Radio improvements.  Better 3G speeds, faster GPS lock?

Well done Nokia “Your decision to partner with Microsoft is as sage and wise as allowing your balls to be shaved by a mental patient.” DrXym (126579), /. Comment #35906170

Olympic National Park

http://www.static-cisco.com/assets/sol/ent/cin/technology_pcast.xml Need to read up on how to properly do podcast, look to see if there are any good android apps to auto-download and arrange, and find my tunecaster.

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