Jun 28

Port Scan Attack Detector

By linc Linux, Security No Comments »

I mentioned on the show on it’s last go round that I was looking for a port scan detector for work. At least I think I mentioned it was for work…. Anyhow, long ago I used to use a program called Portsentry, which still appears to be around, but in disuse. So, I went looking around for other options. The two I ran into frequent mention for were snort, which also mentioned frequently that it was difficult to configure, and PSAD.

Well, it was PSAD that I decided on. I did a little preliminary testing this week. PSAD is easy to install, in fact, there were packages available for RedHat and Ubuntu already. It’s also very easy to configure, just edit the /etc/psad/psad.conf file. All in all I was very satisfied with this piece of software. One particular caveat, though, is beware of running it on a network with windows machines. Not that PSAD doesn’t work well, but quite the opposite. it takes considerable “tuning”, I learned, to get things running nice on a windows network because windows computers flood the network with a lot of unnecessary traffic – specifically udp traffic. Think I am kidding? Try it and see ;-)

Jun 28

My Dog

By linc Home Life No Comments »


My wife just snapped this pic of my dog Precious on her cameraphone and sent it to me. How could anyone not love that face?

Jun 28

RackSpace

By linc Programming, RackSpace, work No Comments »


One of the applications I have been working on at work is RackSpace. Basically, it’s an application that helps track rackmounted servers and equipment and their placement, power, vlan and BTU usage in a datacenter. Of course, this started out as one of those deals where there just wasn’t a utility available that did exactly what we needed. So, being a LAMP programmer, my boss asked if I could come up with something.
This is where I get to tell you all how cool my boss is. He has on several occasions asked me about whether I had made the application available on sourceforge yet or not. I hadn’t until recently had the time to make an installer for it, so now it’s available to the masses here. Enjoy and let me know what ya think.

Jun 22

Crazy Ubuntu and getting Openbox running

By linc Linux, OpenBox, Ubuntu No Comments »


OK, I mentioned before that Dann convinced me to try Openbox. Well I have been digging it so far, but I have found a couple other issues with using it under Ubuntu.

I had been switching to it all along after having my laptops already running, so I didn’t notice until this weekend that when you switch to Openbox as your default windowmanager you lose your network connection. You see, normally Ubuntu has Gnome or KDE start network manager, which starts your network up. Well, being too smart for my own good, I decided that I would just slap the info I needed into the /etc/network/interfaces, where I know Debian and Ubuntu hides that stuff. I told it to start my wireless interface and get an address via dhcp, and I was off and working on the rest of my problems (but this is not the last time I would visit this one).

The next issue I ran into was without gnome or KDE beforehand, how do those Openbox guys get their background going. Well, after trying several programs like feh, etc., I decided I could just get gnome’s settings daemon to do it and then at least be able to keep my background between windowmanager switches more easily.

Then, I found that mysteriously my network connection would just drop. It was a random thing, but quite irritating. After mucking about with it for almost a day I decided that I didn’t remember having my connection go down under Gnome, but it was now under Openbox. I decided to reverse my prior network change and just have Gnome handle it for me.

I dig a bunch of digging into this to see what other people were doing, and they were doing the same as I. How do they get all this going? Well, they put it into the ~/.config/openbox/autostart.sh file. This is, by the way, he file you would use to get anything to autostart in Openbox. So let’s take a look in mine:


gnome-settings-daemon &
gnome-power-manager &
nm-applet --sm-disable &
gnome-volume-manager --sm-disable &
$(sleep 20 ; conky 2>/dev/null 1>/dev/null) &

I put the Gnome settings daemon in there to control my background and screensaver, etc. The gnome power manager in there on recommendation of several websites. It manages suspending, hibernation and screen blanking, etc. The nm applet is the one that controls my networking. Putting this in here started my network right up and keeps it working too. The volume manager should control auto mounting, etc., but I have yet to get it to do anything when I insert a cd. Further research required there. And last but certainly not least, I start up Conky, which displays my date/time (and now battery status). You’ll notice the 20 second sleep command before starting Conky, and that is to allow the gnome-settings-daemon enough time to set the background before Conky starts. If it happens any other way, Conky and gnome have a battle royal over desktop background control and the background/Conky will blink on and off several times before one becomes the victor.

Jun 21

Rest in peace Piggy

By linc Home Life No Comments »


Seventeen years ago, when I was much younger but still very good looking, I came home from a visit to the animal shelter with a surprise. My soon to be wife wanted to know why there was a lump in my jean jacket making a faint meyowing sound. It was a little black kitten that I saved in the parking lot from making it all the way into the SPCA. I had always wanted a cute little black cat, and then I had one. We flea dipped him about 5 times (he was infested) and I put a little collar with a bell on it around his neck and named him Jingles, because that was the only way you could find him at night.

Some days later, as it happens, we found a peculiar “personality trait” in Jingles. He was an absolutely veracious eater. He was the kind of cat that could hear food fall through the air and time warp himself into a place where he could be there to get it before it hit the ground. We started calling him a little piggy, because that’s how he acted, and the name just stuck. Jingles took his own name, Piggy.

Piggy was always true to his name. He was somewhat aloof to strangers, but very loving to his family and quite tolerant of my daughters pulling, poking and prodding as she was growing up. He had his own special separate bonds with my wife and I. He was always my pal and would like to crawl underneath my covers and nap with me when we were alone. He loved for me to rub his belly and he liked to “hold hands” with me. He was my wife’s buddy and constant companion and liked to park himself on her hip while she was sleeping, keeping her warm.

These last few months have been hard on Piggy. He started to go slightly senile due to old age, and when he started slobbering, we took him to the vet and found that he had cancer in his mouth. We got him on some meds that seemed to help out a bit and made him feel more like himself and decided that we would let him tell us when it was his “time”.

Well, all that changed tonight. He was eating in his usual spot and fashion on the counter and jumped down when he was finished. As soon as I heard him hit the ground he started screaming and ran into the hallway. He continued to howl and paw at his face and he was bleeding pretty badly. I let him calm down for a few minutes before going to take a look at him. His jaw was pretty swollen and he was still bleeding a bit. I knew he was in pain a decided to take him into the vet. I was under the assumption that because his teeth were shifting around due to his cancer, that maybe he bit himself or broke a tooth or something.

A trip to the vet revealed that the impact likely broke his jawbone, which was weakened due to his cancer. We had to have him put to sleep just a couple hours ago. He was in considerable pain, had no chance of healing and would no longer be able to eat. I got to “hold hands” with him as he made his journey. I will miss him greatly as will the rest of my family. It’s very hard to lose a close family member like that. Goodbye Piggy. I love you.

Jun 20

Clean new look

By linc Linux, OpenBox, VMware No Comments »

At the behest of Dann, the other night I installed the Openbox windowmanager. I have to say I am pretty impressed with it so far. With no icons, task bar, etc., to clutter up your screen it leaves more realestate there for you to fill up with your favorite and more productive things. Not to mention it’s dang fast!

Now there are a couple things I had a problem with (aren’t there always). The first being that although I really could care less about the lack of taskbar, I was at a loss for a clock/calendar. After some trials and surfing around I found the perfect solution for that was Conky. now Conky does a lot more things than show the time, but in my case it fit the bill perfectly. I configured the .conkyrc file to do some transparency and put only the system name and the time/date on the lower left hand corner of the screen. The code for that looks like so:

own_window_hints undecorated,below,skip_taskbar
background yes
double_buffer yes
use_spacer yes
use_xft no
update_interval 30
own_window_transparent yes
alignment bottom_right
gap_x 10
gap_y 10
draw_outline yes
TEXT
$nodename
${time %D %H:%M}

The other part of that was the calendar, but I had forgotten how easy it was for me to just run “cal” in an xterm, so that solved that problem too ;-) The last frustration was a wierd error I was getting using Openbox. After a few minutes of use the ctrl-alt arrow key switching of the desktops would stop working. After some trial and error I found that this behavior only happens when I am running vmware server. I assume it’s due to the way that program handles screen controls. As soon as I turn the vmware server console display off and restart Openbox, the problem goes away. I can probably live with that too, but if anyone knows a better solution, please let me know.

Oh yeah, and if you haven’t yet tried Openbox, you should. It’s rockin’!

Jun 07

Linux training

By linc CentOS, Linux, RedHat, Slackware, work No Comments »

I am sure some of you have been wondering why I recently dropped off the face of the earth. Well, my company sent me to RedHat training last week.

Now most of you know I have been “doing” Linux for a very long time. Some of you may recall that I used RedHt early on, however, I was disenchanted with them around the RedHat 6.0 (pre Enterprise) when they started messing with their compiler, etc. I switched to Slackware at that time and haven’t really used RH until a year ago when I was hired as a Linux admin in a primarily RH shop.

All that being said, I went to some intensive RedHat training last week and I have to say that not only did I learn an enormous amount, but after working that hard with RHEL, my opinions have definitely changed. RedHat has come a long way baby!

The primary problem with RedHat that I used to see was rpm. I absolutely hated to be stuck in rpm dependency hell, where you would try and install an rpm only to have it tell you that you needed to fill a dependency first, and then have that one tell you the same thing until you were just fed up with the whole process. Well, this has been addressed with RedHat’s adoption of YUM. Yum now takes care of dependency tracking and fulfillment similarly to apt-get.

Once I realized that hurdle was past, I started to appreciate the huge strides that they have put into getting their Linux product enterprise ready. There really is a lot of spit and polish that has gone into things since the last time I really looked under the RedHat hood. If you haven’t looked in a while, I encourage you to do so.

The thing I was particularly impressed with is the uniformity and ease of service installs. Now I know that many of you are used to installing things like bind and dhcp and apache and sendmail/postfix, etc., what have you, on lots of other linux platforms, but there really seemed to be a uniformity to all this under RedHat, and the initial configurations or supplied config files seemed to be saner somehow. Most notably to me was the difference in ease of install for bind or sendmail between RHEL5x and any recent Ubuntu release. It could be that I had the training manual in hand, but it just seemed more ready to go and easier to change the config if you had to.

The other thing I have really come to appreciate recently, partly because of my job, is the enterprise attention to securing the server. RHEL does a good job at this with asking you for information during the install to help you start out with a working firewall and SELinux set up and running. Now, while I still see SELinux as a huge pain in the behind, the fact is that it does do it’s job if you let it, and does it well.


And, since I had spent a week doing RHEL and deciding it really is a good distribution choice for servers, I wanted to see what I could do for home use. Now RHEL costs some money, and if you are a business, and maybe even personally, the price may be right for support and the use of the RHN (RedHat Network), but for me, I want something a bit more inexpensive. Yeah, I am cheap ;-)

Basically, there are 2 well known RedHat derivatives. The first is Fedora, which is a community distribution that RHEL is actually based on. Fedora is a lot more bleeding edge than the current RHEL, though, so in some instances, things just don’t match between the two. My personal criteria, however, is to be able to use something at home that is as similar as possible to what I use at work. For that, I turned to CentOS, which is a distribution that is compiled directly from the RHEL sources and rebadged.

I have done a couple installs, a lot of poking around, some direct comparisons with the RedHat manual in hand, and I can state that this certainly seems to be the case. Everything I have done over the past week has direct application to my CentOS server with the exception being the logos and color scheme (and I actually like CentOS’s better).

Now, I probably won’t be using CentOS for a desktop or workstation anytime soon. And I probably won’t be using it as the ONLY type of Linux server either, after all, I really still love Slackware, but chances are very good that I will be running CentOS at home somewhere and surely RedHat at work. If you’re looking for an enterprise level Linux server environment, you really owe it to yourself than to give one of them a try.

Verdict = It’s good stuff!

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