Greylisting…Again
by Nick on Dec.02, 2009, under E-Mail, News, Security, Software
Certain…Parties… Have intoned I am goofy for implementing weird “mail bouncy thing” that is sometimes frustrating and is a silly anti-spam technique. Well, that would be Greylisting, and while it’s weird, it also drops a lot of spam getting through.
FreePBX and PBX in a Flash
by Nick on Nov.25, 2009, under Administration, News, Software
Very cool for dinking around, PBX in a Flash installs CentOS, Asterisk and FreePBX all in one go, with a couple of extra scripts. It definitely shallows the learning curve of Asterisk. I basically followed this Nerdvittles tutorial, and now I’ve been setting up Queues, IVRs and Voicemail. I still can’t figure out how to get someone to log into a Queue… Oh well. Very fun.
“It Worked Yesterday!”
by Nick on Nov.09, 2009, under Administration
[Originally Appearing on http://blogs.iphouse.net]
The three most dreaded words a support technician can hear are “It Worked Yesterday.”
That phrase has a hidden implication trailing after it “…so what did you do?”
Well, usually, we didn’t do anything. People can accept that a car, or a furnace, or a TV can break someday out of the blue. We all know that those are machines, and we have some idea of how they work, and that they do break. The problem is, not a lot of people realize that computers are machines too. Sure, If you ask someone if a computer is a machine, they’ll say yes. However, if you show them the inside of a computer tower, they’ll usually shake their head and say “Is that it?”
It’s been clear, over my many years of tech support, that people think their computer is a magical device. And since it’s magical, it should work a certain way. Forever. And when it stops working, some mysterious outside forces conspired to break it.
My brother thinks this way. To him, a computer does what it’s supposed to, and then it stops. Then he calls me, and to him, I cast a few magic spells, prod at it chanting while waving a censor of incense in the air, and it magically stops working. They I mumble in a strange, arcane language about what went wrong. He smiles and nods, and the magic box runs again. For a while.
But when it breaks, it’s the ISPs fault, or his wife “touched something” or a computer virus caused his machine not to power on.
I tell him, it’s not any of those things, it’s him. It’s us.
Computers are beholden to humanity. They suffer from our lazy programming, our dusty houses, our animals that chew on their wires, our neurotic ticks causing our legs to kick them. Computers suffer this day in and day out while we curse them, berate them, and blame them for everything we all ultimately did or failed to do. Did install an anti-spam program. Is your computer is slow now? Did you visit customcusors.biz.co.tg? Is your hard drive always making noise? Did you forget to update your operating system? Is your email program acting erratically?
Do yourself a favor. Update your operating system. Blow out your computer’s fans and vents once and a while. Don’t install every security program ever made. Don’t install trinkets that were programmed by the lowest bidder. Treat you computer well, and it’ll treat you well.
Well, until it magically breaks one day.
NFS + Openvpn
by Nick on Nov.03, 2009, under Hardware, News, Software
Hey, it works! I’m moving a file (on a GIG-E switch between VLANs) at around 3MBps.
Thanks to http://linux-bsd-sharing.blogspot.com/2008/09/howto-setup-nfs-server-on-freebsd.html
Postfix MySQL and You!
by Nick on Oct.30, 2009, under Administration, E-Mail, News
Postfix is surprisingly flexible. When I initially set it up two years ago, I set it up to reference a database, but I had a flaw in my logic. Basically, Postfix had no idea if a domain was marked active or inactive in the database. All it knew was whether a domain was in the database or not. Postfix has a default query, that looks for key information. However, you can supercede it in your config files. So I simply commented out the old variables that it passed to the default query, and wrote a new one:
user = DB_USER
password = supersecretpassword
hosts = 127.0.0.1
dbname = DB_NAME
table = domain
#select_field = domain < -- old version, commented out
#where_field = domain <-- old version, commented out
#New Query:
query = SELECT domain FROM domain WHERE domain='%s' and backupmx = false and active = true
Yes, I have backupmx enabled, even though that’s a titanically bad idea, and I would never use it. Why is it a bad idea to fuction as a Backup MX server? Because spammers don’t play by the RFCs and often send spam to lower weighted MX records in an attempt to bypass spam protection.
But I never know what people may ask for in the future. ![]()
Oops…
by Nick on Sep.24, 2009, under Administration, News, Software
This is a live and learn moment. When I did my last update, I had a lot of old libraries hanging around. I thought that portupgrade would recompile all of my ports, but it didn’t. Most had been recompiled in the interim as I had been upgrading, but Apache, well, Apache upgrades are hardly for the weak. So, when I deleted a bunch of crud laying around. I broke SUEXEC. SUEXEC is what allows scripts to be executed under my various users’ home directories. Well, a recompile and reinstall, and things are working much much faster. Always fix your architecture kids.
IOS and JUNOS
by Nick on Sep.15, 2009, under News, Software
I’ve decided to get my learn on, so I’m going through Juniper and Cisco training material. It’s fun, actually. Juniper certs are free, for now, so I’m starting there. Most of their material seems to compare JunOS to IOS anyways so it’s a two for one. Now to get a lab going…
Calls from AT&T to Google Voice are not allowed.
by Nick on Aug.26, 2009, under News, Security
It seems that they are being blocked. I called technical support and requested that the “Case be escalated.” From my limited experience, this seems to be an AT&T issue, as I can reach my Google Voice number from a landline, and I’m not getting a fast busy, or other such errors. If this is not resolved in 24 hours, I will be filing a complaint with the FCC and MN’s Attorney General.
Curiosity
by Nick on Aug.21, 2009, under News, Security
People are so curious nowadays… Today I’ve received one NMAP ping from Colorado State (I’m guessing since I recently downloaded NMAP) and one “Version” query from ISC.org. Or at least, I think I have. Oh well, no harm done.
Ok, “ClueBringer” has some problems but it’s neat.
by Nick on Aug.10, 2009, under E-Mail, News
Spam is fun. Watching spammers in action is even more fun. Via a friend, I have a very old domain that for which I handle mail. Since only one address is legitimate, it’s easy to use a wild card alias to catch and analyze spam. I implemented some Policies via Policyd2, aka “ClueBringer” (linux kids are cute, aren’t they?) Basically, I added a 20/hour recipient quota, and a 5/hour /24 based sender quota, hoping to bounce a few messages. It never happens. The bot network that sends these messages implements a simple, but effective interpolation scheme where the same address NEVER receives mail from the same ip address, and it always jumps /24s after 2 messages. It’s fascinating to watch.

