Seeing as I have taken quite an interest in this, I have decided to forget about just alright free hosting on wordpress.com, and I have moved to a full on host :)

The new website is:

http://talesofacoldadmin.com/

Not too much different, but a LOT more stuff to play with for me :)

I hope you guys continue to read, and enjoy!

Its very nice, I like very much

Essentially the grant (and simulations) are to find a better way to organize memory. If you think about the way that memory is in the conventional sense, you have programs interacting with first the CPU cache, then to the RAM, then to the HD as a ‘last resort’. Got it. Right.

What he’s aiming to do is essentially provide another layer between the RAM and the HD (and in the future between the RAM and the CPU cache) that essentially has an algorithm to organize it, both physically (reducing copper wire latency) and programatically (in page size, as well as frequency of use). I’m not too sure on the specifics past that, and that was only one branch of what he’s actually researching, but it struck me as quite interesting!

I’m hoping at some point to get job management going properly, as well as “actual clustering” going. Right now people just ssh into the head, and have a trust setup between head and nodes, so they don’t have to login after they’ve authenticated through the head. The nodes are pretty easy to start and compile code on, so it works for all the simulations, at least for now.

Every node is running Redhat Enterprise Linux 5, and the simulations are written in C. I’ve got everything setup to kickstart whenever I need it. Take tonight for example, my nodes have been mysteriously dying, and I have a feeling that someone’s code corrupted something in the T3 module, and they just kept trying to run it on all the nodes.

Thankfully I have set it up so its nice and easy to wipe everything clean. Thank god for kickstart, this is a copy of mine :

http://pastebin.com/f6c745c08

Running through my kickstart, you see that it puts every node on the same NIS domain (btdpool.ee.mtu.edu), and uses an ftp server to grab all the necessary packages and files. No X windows, as there isn’t a need for it. Generates the swap partition depending on memory size, and fills the rest of the partition with ext3 (forget LVM!). Installs all the packages it really needs, and on the post install it does the following:

Changes the passwd binary for all nodes to yppasswd, so when people try to change their password, it propagates properly through the NIS domain.

Adds “+::::::” to /etc/passwd – this basically states that the rest of the file should be looked up in “Yellow pages” (or the NIS server, whichever you prefer :-P )

Adds “+:::” to /etc/group, and does the same exact thing as the previous one, but with groups instead of passwords.

Puts an entry in /etc/fstab to connect to the NFS share I have running for everyone’s homedrive, allowing SSH trusts to remain in place no matter how many times I wipe them :).

These things seem relatively simple…now. Trust me, it took me many many hours to figure out exactly what I needed to do to get everything working like this. Now all I have to do to “refresh” the nodes is PXE boot them, and reboot after they’re done. Since nagios only checks SSH and ICMP connectivity to all nodes, it will still be fully functional.

All in all, it has been a huge learning experience for me, getting to know a lot about RHEL administration. It’s been a lot of fun, and I’ll get into all the scripting that I did to make everything work flawlessly :).

I’ve got a lot of things happening using cron and bash scripting, but I don’t feel like getting into that right now.

Also look at the blast from the past that I found today at work!

Top

Right

Front

Left

Back

I saw it sitting there and literally burst out laughing. There was a huge cart of old crap sitting on the left when I walked in and I spent about 20 min digging through it for nostalgic things like this :).

]]> http://talesofacoldadmin.wordpress.com/2009/11/11/my-cluster-making-ram-faster-with-every-simulation-hopefully/feed/ 0 lucywitdiam0nds Top http://imgur.com/Y9CjL.jpg Front Left Back http://talesofacoldadmin.wordpress.com/2009/11/11/lopsa/ http://talesofacoldadmin.wordpress.com/2009/11/11/lopsa/#comments Wed, 11 Nov 2009 05:44:10 +0000 lucywitdiam0nds http://talesofacoldadmin.wordpress.com/?p=207 ]]> Horay! I just joined the League of Professional System Administrators.I have a feeling this is going to be a good outlet for both learning as well as finding contacts in the future. I joined on the advice of Matt Simmons, so thanks for letting me know about it!

If you’re interested in System Administration, you should check it out, its only 25$ to join if you’re a student :).

http://lopsa.org/

Also I joined both of my zeroshell tutorials together into a page, check it out!

http://talesofacoldadmin.wordpress.com/migrating-from-linksys-linux-with-vpn/

It all comes back to Apple. I know it sounds a bit werid, but they inadverntently forced microsoft to adhere to stricter conventions to improve the overall stability of their OS.

Something like 90% of all windows based crashes (blue screens of death) are caused by 3rd party drivers functioning improperly. I can see it being the issue because there is very limited checking when it comes to drivers in the first place. Drivers are written mostly in assembly, which means to have something to test if it is going to interact with the windows kernel fine is a damn near impossible task.

This is where Apple actually does something right. They control every aspect of the hardware and software with their computers, which means that all their drivers are professionally written, and tested throughout for stability. When I came to that realization I felt like someone had slapped me in the brain. Apple…did something RIGHT?
I’ve been a longtime advocate for Windows and Unix-based operating systems (EXCLUDING Apple’s OS) for obvious reasons, and seeing that Windows 7 is taking a leaf out of Apple’s book is a bit weird for me. Its still a pain in the ass, as with most Apple based decisions, but it is almost necessary for Microsoft to improve the stability of Windows.

I understand Microsoft’s mentality on this, but it should still acceptable to use unsigned drivers when you really want to, perhaps with a warning that it may cause stability issues.
Namely – I want to be able to use my hax0red Xbox controller damn it! (And yes I know that the Xbox used USB with a different port configuration :-P) it is the one thing that doesn’t (and will never) work on 7 unless I reboot and go to “disable driver signing”, but when I restart it re-enables it :(. Sure there are ways to edit your bootloader to always boot into this special debug mode, but wtf. WHY?

http://www.killertechtips.com/2009/05/05/disable-driver-signing-windows-7/

The only reason for this is the fact that you have to have a valid certificate from VeriSign ($300-$400 a year!)

http://en.wikipedia.org/wiki/Criticism_of_Windows_Vista#Driver_signing_requirement

Shenanagins I say!

(In the time it took me to write this article my hits jumped up to 11,114 hits! Holy crap!)

So coming back to my previous post:

Getting DDWRT to play nice with Zeroshell

After getting everything working properly with routing set between interfaces, we can utilize one of the coolest functions of Zeroshell, VPN access (almost) out of the box.

Getting VPN to work:

For those of you who don’t know what VPNs are, it stands for Virtual Private Networking. It is simply a method of securely connecting to your home network, as if you were physically wired into it, when in fact you are connecting over the internet. This particular method wraps the VPN in 2 layers of security – X.509 Cert and a Kerberos server. Plenty of encryption for an enterprise solution (small scale of course). Keep in mind that you can set this VPN server’s authentication in one of 3 ways: X.509 certificate, Username/Password, or both. In this case, we’re using both.

You need to make a couple decisions though at first.

• Do you want to have just one user on your VPN?
• Do you want multiple users with the same username? (not necessarily recommended)
• What authentication do you want to set up? (credentials + X509 is what i’m using in this)

To start go into the users section on the left, select the admin user and click the X509 tab at the top, which will give you lots of information about that particular user (and any subsequent users as well)

We need to export this certificate and place it in a good location. You should name it to admin.pem if it isn’t already.

This is only one of the certs we need though. We need to the something called the “Trusted CA”. CA stands for Certificate Authority. In the world of certificates, this is a trusted source. The administrative entity that is considered ‘always valid and all knowing’, which in our case is our Zeroshell install. As long as the CA says its fine, any services using it will trust it, much like SSL certs.

Now we need get a copy of our trusted CA and enable the actual VPN functionality of our Zeroshell. What you want to do is click on the Trusted CAs button under the X.509 Configuration, which will spawn a window. Export it as a .pem, and put it somewhere safe.

Now to enable VPN functionality we need to click the ‘enable’ box, and click save. Complicated, right?

Next we need to get a copy of the OpenVPN client. Since I’m using Windows 7 i had to get a RC, with a proper signed driver (shakes fist at microsoft). Also make sure you run the installer in compatibility mode for windows vista and run it as administrator (what a pain in the ass):

http://openvpn.net/release/openvpn-2.1_rc19-install.exe

The newest installer can be found here, but it didn’t seem to work for me when I installed it :(

http://openvpn.net/release/openvpn-2.1_rc20-install.exe

After getting it all installed and whatnot, move CA.pem and admin.pem to:

C:\Program Files\OpenVPN\config

or in my case (64 bit machines)

C:\Program Files (x86)\OpenVPN\config

Now get into that directory and create a file named config.ovpn and copy my config from:

http://pastebin.com/f6c913fcd (edited from the Zeroshell OpenVPN configuration – thanks guys!)

Now just edit the first line to hold whatever your server’s IP is, and proper port if necessary. You probably want to decrease the verbosity to 3 after you’re sure everything works as well. You should now be able to start the OpenVPN gui, which will start a taskbar icon.

Right click and go to connect, and it should prompt you for a username and password, log in with the admin user, unless you have other users to use.

You should now be successfully connected to your VPN in a very secure manner!

Getting NAT working:

Alright, for those of you who don’t know what NAT is, it stands for Network Address Translation. This is a fancy way of saying port forwarding, which does exactly what it sounds like it’s doing. It forwards a port on one of your clients to the outside world, so that anyone looking at your router from the internet will ‘see’ into your network.

First about my interfaces:

ETH00 is my internal network 10.0.0.0/24

ETH01 is my WAN port, connecting me to the internet

So the first entry in my nat table:

I have an FTP server running on port 21 of my laptop which I want to be able to access from anywhere. In order for me to make it so I can connect to my external IP on some port and talk to my laptop, I need to tell my router what to do.

If you go into the router section on the left, and click the virtual servers tab at the top after that, which will spawn a window for you.

For whatever reason you need to specify your internal interface (the one that takes care of your internal network), which in my case is ETH00 to any IP address (you can restrict services like remote desktop to a single ip, or a range of IP’s if you want.

The local port box specifys the port you want to connect to from the outside

The remote IP is the local IP address of the machine you want to forward to the outside

The remote port is the local port running on said ip address

In this example I have an FTP server running on port 21 on my local network, which is getting forwarded to port 65534, so in order for me to connect to my laptop I need to connect to my.external.ip.address:65534 to talk to my laptop properly

The same goes for all other services, for bittorrent use the same port for local and remote ports, and it’ll be a 1:1 portmap to your local client. Tis truly handy :)

The proofs in the pudding:

C:\Users\P0rT_Smoke>nmap -T4 -sV -p65534 71.xx.222.63

Starting Nmap 5.00 ( http://nmap.org ) at 2009-11-09 22:12 Pacific Standard Time

Interesting ports on 71-xx-222-63.dhcp.mrqt.mi.charter.com (71.xx.222.63):
PORT      STATE SERVICE VERSION
65534/tcp open  ftp     FileZilla ftpd 0.9.31 beta
Service Info: OS: Windows

Service detection performed. Please report any incorrect results at http://nmap.
org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 2.42 seconds

So hopefully now you have an awesome network setup allowing you to securly access any local resources you may  need, as well as foward services you can afford to have ‘on the wire’.

Nmap is your friend!

See, even Trinity used nMap to save all of humanity. It can work for you too!

He said fiber optics, and I figured, you know alright, just another fiber optic whatever. So I dug a bit deeper, and it turns out he’s working on getting fiber optic integrated circuts to work. Let me say that again FIBER OPTIC CIRCUTS!!!

As soon as he said that I immediatly had 10 ideas in my head, and we branching into our seperate directions, and this interested me so much that I walked away from the elevator that I was waiting for just to talk with him about it.

As any EE major knows, the reason that we use serial communication as opposed to parallel communication is because of the fact that we don’t have to worry about syncing the clock (the force telling your circuts on what interval to do something).

Data used to be transmitted like this:

0-=============-0

1-=============-1

2-=============-2

3-=============-3

4-=============-4

5-=============-5

6-=============-6

7-=============-7

This is known as a parallel transfer because, as you can see data lines travels in parallel with one another.

As IC’s get smaller and more efficient, the distance of the copper wire starts  to effect the latency of copper wiring. In short, the minuscule length differences between 6 and 7 would cause their signal to be just the slightest bit off.

This used to be fine when we had a long clock period, but when you turn the clock frequency up (and thus increasing the speed of your circuit) there is a major problem of getting the signals to sync properly.

Then someone figured out that you could multiply your speed much past that with parallel connectors using a serial connector with an embeded clock signal.

This allows for us to turn the clock WAY up and get a major performance boost, as we no longer have to deal with different length connectors throwing our main clock off.

Essentially what this boils down to is the fact that we can now take all these super-fast serial lines, and run them in parallel again, giving us a multiplaction of throughput, thus shattering yet another bottleneck in the computing industry. Amongst other things.

How about not having to worry about your circut “shorting out”? We can literally take this theoretical circit and have it water-proof in nature, because we’re using lasers (which still conduct under water, not to say they won’t be refracted though)

Needless to say, I’ve been thinking about this for a while now, and I am still just stunned at the implications.

Imagine your next iPod having a few million of these in it :-P

Then the internet will REALLY be made of tubes

I just can’t wait to see how they actually implament this into circuts. Interesting!

Id like to figure out what exactly is going on with them before I just nuke everything, although for time’s sake, I might end up doing just that.

Oh well, its probably just someone’s crappy code breaking each node. At least its only been one at a time, and it doesn’t look like there have been any jobs submitted in a while.

I’ll probably end up pulling that apart tonight (if I find time between editing my first and second posts), although the biggest pain is the fact that I almost have to be there to see what exactly is going on.

::shrugs:: time for some learnin!

Stopping in to check on the nodes, I saw the following two screens for dmesg | more :

It looks as though eth0 is having a hardware fault, and gets stuck with MAC_TX_MODE=fffffff although i’m not sure what that status means exactly, i’ll figure it out though, as this problem is whats been affecting all of my nodes, and if people can’t connect to them, obviously they can’t be used for computations :(

I’ll post more when I actually know what’s going on. Open to suggestions though!

Hopefully I’ll be able to figure this out without wiping all my nodes clean. That would be kind of a pain in the butt.

This is a pretty bitchin rendition of panic.c (kernel panic)

So it seems like a bug in the tg3 driver, which drives the NIC. Although my money is still on a hardware failure that is tiny but there. I sincerely hope I’m wrong, but I’ve diagnosed a lot of failures like this in the past, and its generally turned out to be something that is just going to get worse :(.

I’ve got ideas to expand this article, so check back in a few days and it should be fully finished :)

This is my network infrastructure.

Click for a bigger picture (small formatting space :( )

So now you see exactly what it is I want to do. I had everything running off of my DDWRT on my WRG54G, but my roommates and I use quite a bit of bandwidth and with 8 mb on onboard memory, needless to say it was the equivalent of a one armed retard trying to take on an army of ninjas, even with overclocking enabled.

I’d been looking for a computer to turn into a router for a while, and I finally found one at work last week :)

So I grabbed a copy of zeroshell, and started it up and I was greeted by the main screen. It sets a static IP on eth00 (their naming convention is a bit wonky) to 192.168.0.75, so I plugged into it with my main ethernet port, and set a static ip to the same subnet (google it if you don’t know how).

When I could finally connect I was greeted by the sign I page (of course after the SCARY self signed cert warning)

Default U:P == admin:zeroshell

Time to create a new profile, on the top bar, there is a ‘profiles’ tab. Its a good place to start so we can actually save all our settings :)

In this case, there was a WIN95 formatted drive in there, which zeroshell couldn’t read. What I ended up doing I just plugged it into an ide reader and formatted it, which worked fine.

Either way after creating a new database with all of my info, including hostname, Kerberos, and LDAP stuff.

Now in the ‘Network’ tab we need to set our IP addresses. The dynamic IP won’t stick until theres actually an address to get, so I just set the static IP to 10.0.0.1

It was at this point that I realized that I needed to disable all DHCP/routing functionality on my DDWRT

Logging in I had to change a few things

• WAN Connection type = disabled
• Local IP address = 10.0.0.2/24
• Assign WAN port to swtich
• DHCP Fowarder (as opposed to server) – followed by the ip of the dhcp server

Since I wasn’t going to be changing anything on my wireless side (I still wanted to use the AP functionality of my DDWRT) there was no need to fiddle with any of those settings.

Finally all we have to do is disable routing. Go to the administration tab and at the bottom hit the Routing button to disable.

Now we can actually put our machine into place, but you may want to enable the dhcp server first (or you have to assign yourself a static address):

On the left in the ‘network’ subsection theres a DHCP link, after you click it you need to create a new subnet. Choose the proper interface to broadcast on (eth00 in my case) and set the dhcp pool specifications. I did 10.0.0.10-10.0.0.25 and put in OpenDNS for my primary and secondary DNS.

Now you want to get a dynamic address for your ‘outside’ interface (eth01 in my case)

Now we need to click on the Router section, and click the NAT tab, so we can route between interfaces properly.

Thats about it as far as what needs to happen to get routing, DHCP, and dns properly set up so you can now do pretty much anything you want.

The important lesson here? Before you start messing with things that could break the world, which in turn causes you to mess up your hard drive containing your configuration, BACKUP YOUR CONFIGURATION. Do it now. Seriously. Although I wouldn’t have written this article if I would’ve done that now would I :)

I apologize for the crappy formatting. I just started this thing, so I’m still trying to find a theme that supports the architecture of my writing, and still looks good.

Like I said, tomorrow I’ll put in my OpenVPN how-to on the end of this article, as it can be a bit complicated if you don’t know anything about certificates.

After that I’ll be putting in how to get NAT working properly, as it can be a bit weird. Took me a while to figure out anyway.

Identity theft is not a joke, Jim!

EDIT: So instead of putting the VPN & NAT stuff down here, I’m going to just do another post about it, tie them both together and make a page for it.

Hope you enjoy it!

Le sigh. That is all I have to say about milw0rm being down for so long. I mean obviously I don’t really use it for exploits, as there really aren’t any viable ones (good in a crunch though if you DO find an unpatched system though) after patching and such, but I miss reading about the ones that they DO have.
I mean come on, this was like the first security-oriented website I REALLY started reading, and that was all because of a bookmark toolbar enclosed with backtrack 3 (or was it 2?).

At least I still have darkc0de.com, a great security oriented forum with programatic POC’s that are very helpful for learning both optimized coding and how many security exploits are actually written.

For me security is something that has fascinated me from the start. To me theres nothing better than finding a failure in a system that can be leveraged to do something proactive and offensive. Not offensive in the malicious sense per say, but failures are generally considered a shortcoming, something that the system is lacking. The ability to transmute this failure into something that accomplishes another task is damn near like alchemy.

I make no claim to be an expert in any sense. I am a student, and I always will be. I break things, but that is a natural path to take when trying to become intimately familiar with a system of any sort. I am just curious, and while this has gotten me in to trouble in the past, id rather have my curiosity then be oblivious to anything security related, because that is how bad administrators are made.

You can make any system secure enough that it isn’t worth a hackers time. That is the number one thing, even if your good, you need all the information before you can even remotely evaluate the most vulnerable spot. While its true in some sense that any system can be compromised given enough time, that also assumes that the system is static in nature. As computing grows more and more powerful, it also gets more dynamic. People are starting to write software with security in mind, and while there will always be bad sys admins and bad programmers failing miserably, we are seeing our world transition from a hacked together system full of bugs to a beautifully built juggernaut of entropy. All security is security by obscurity, but we’re talking about trying to find a needle, buried a mile in the earths crust, from a different galaxy.

On a different note, its getting way to dark way to quick. Its 6:00 and its pretty much black. An average day for me starts at 2:00, so needless to say I’m not going to be getting much sunlight so far up here. This is the part that kills me about being up here. It’s cold, lonely, and boring. Don’t get me wrong. I love cold weather and snow, but when it’s too cold for me to go snowboarding (one of the ONLY ways I can relieve stress up here), thats where I draw the line.

My freshmen year up here, we had 1 snow day, and thats all I’ve seen in the past 3 years. It got down to -35, and nobody’s car would start :-P

I have a feeling I’m going to be writing a lot more articles this winter.

http://talesofacoldadmin.wordpress.com/bash-shortcuts/