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2009-10-16

Using SPF Records To Build Objects

My biggest complain about modern firewalls is their lack of the ability to create rules based on URLs or HTTP streams; you have to open access between IP addresses.  Yes, I know there are other means to do that, but I want my ASA/PIX/FWSM to do it without making me do so much work. Anyway, […]

2009-10-01

Object Groups in the ASA/FWSM/PIX

I can’t believe I haven’t talked about object-groups yet.  I had a whole other blog entry written up, and, when I went to link things over, I realized I couldn’t find an intro to it.  Here it goes. Welcome to the modern world.  A world of wonder.  A world of quickly-advancing technology.  A world where […]

2009-09-11

ASA and Proxy ARP

Wow.  A new entry.  Everyone sit down before you pass out. I’ve got a real-world example for you today.  We have an ASA 5540 installed at a business unit with interfaces in multiple networks, including one containing the production servers and another containing the accounting servers.  The production network sits on a 7600 that’s not […]

2009-08-19

Getting Temperature Data from a 6500 via SNMP

I apologize to my adoring fans (both of you) for the lack of posting.  I’m in the middle of moving, buying a new house, selling my current house, getting a mortgage, etc.  I’ve up until 11:30 nearly every night filling out forms and going through red tape.  Don’t get me started on getting money from […]

2009-08-07

Aaron’s Worthless Words is 2 years old!

I can’t believe I stuck with something for 2 years.  I usually get a month in before I get bored and give up. Anyway, 2 years ago this month, I wrote a terribly-written article on The Principle of Least Privilege.  Since then, though, my writing has improved (at least, I think it has), the topics […]

2009-06-23

BCMSN Notes – EtherChannel Distribution

EtherChannel lets you aggregate links into one logical connection, but the distribution of traffic is not uniform.  It does not use per-packet load-balancing or the like to determine what interface in the bundle to use.  Instead, it uses a XOR function on packet information to generate a hash that is used to determine what interface […]

2009-06-09

I’m Still Alive

I promise I’m still here.  It’s just vacation time, and I’ve been slacking.  On top of that, I’m doing some work-travelling this week, and that really puts a damper on your schedule. I’ll try my darndest to get some new stuff up this week.  I know there are people rolling around on the floor in […]

2009-05-21

BCMSN Notes — STP States

I’ve decided to take on the CCNP certification, so I’m going to wind up with a few posts will be more my own notes than anything.  🙂 A switch port on a 2960 comes up with a default configuration on VLAN 1.  What happens from the perspective of spanning-tree? First, the port comes up on […]

2009-05-04

How Do You Know?

I’ve got a non-technical one for you today.  If you’re paying attention to stuff around you, you’ll probably end up with a little paranoia after reading this. We’re having another circuit installed, and the LEC came out to do their end-to-end testing.  The tech, Dan, calls me up on the phone and tells me who […]

2009-04-30

Using SSH to Run Commands on a Router or Switch

SSH is more than just a shell.  You can copy files from and to a server or piece of network gear with it.  You can use it to tunnel traffic.  Possibly my favorite, though, is to use SSH to run a command on a remote box without interacting with a shell. One of my biggest […]