Friday, December 17, 2010
Wednesday, December 15, 2010
Monday, December 13, 2010
Friday, December 10, 2010
Wednesday, December 8, 2010
Monday, December 6, 2010
Friday, December 3, 2010
Saturday, November 20, 2010
Wednesday, November 17, 2010
So Wednesday Matt helped me with rsync. The two echo commands are from another script I found on the internets. As you can see the the script runs the rsync command and makes a log of what happened and appends the date to it. I included comments with what the parameters do since there are so many.
echo $’\n\n’ >> rsync.log
rsync -avzogtph /home/sysadmin/stuff/ firstname.lastname@example.org:/home/sysadmin/backup/
echo “Completed at: `/bin/date`” >> $LOGFILE
#-a archive mode
#-o preserve owner (super-user only)
#-g preserve group
#-t modification times
#-p preserve permissions
#-h human readable
I will talk to Devin about getting it set up.
Friday, November 12, 2010
echo $’\n\n’ >> $LOGFILE
rsync -av –rsh=ssh $SOURCEPATH $DESTUSER@$DESTHOST:$DESTPATH 2>&1 >> $LOGFILE
echo “Completed at: `/bin/date`” >> $LOGFILE
Thursday, November 4, 2010
Monday, November 1, 2010
What did I accomplish during 1st quarter?
First quarter Henry and I (and with the help of Matt, wouldn't have figured out bullcrap config without him) set up the LTSP server. That's the major accomplishment. After that we both set up static leases, ingenious hostnames and are now studying for the LPIC.
Did my accomplishments meet my expectations? Why or why not?
Yes/no. When I walked into the lab day one my first thought was to get that LTSP server working completely and hadn't really thought of anything else. I do have the LPIC which is ongoing so I can't say I have accomplished that. So yes I did meet my expectations but that was my only expectation.
What did I learn during 1st quarter?
I learned the linux from the LPIC somewhat. Still ongoing. I could probably set up another LTSP server no problems next time. I can't say I learned one exact topic like I learned networking (which I did last year) but I have learned a bunch of different linux things. I also did some slight documentation. Yay google docs.
In what ways will this knowledge be useful to me in the future?
Pretty much everything I have been doing can and probably will be useful to a sysadmin. Even if I don't become a sysadmin everything is still relevant to someone who likes linux which I don't plan on abandoning. Hopefully they'll get some vidya games.
What new skills did I aquire? What can I do now that I couldn't do when the 1st quarter began?
As I said I learned some linux stuff like tcpdump and other commands. I have a better grasp on commands I already knew. Like kill for example.
What will be the focus of my learning during 2nd quarter?
My focus of learning for second quarter is studying for the LPIC. Maybe the schooltool server depending on what is going on with that.
What new skills do I plan to aquire during 2nd quarter?
More linux. As in skills to more efficiently run a lab/network.
What do I plan to accomplish during 2nd quarter?
Finish with the LPIC? LPIC LPIC LPIC LPIC. That's my main goal. Finish studying for it and get it over with.
Friday, October 29, 2010
I flipped forward a bit and read about Special Characters many of which I know of. Examples are the && which performs a command if the first command succeeded, | pipe which pipes the output to a program, || like and except if the first fails THEN it performs the second, ; which just executes command and finally > and < which pipes the output and input into a program respectively.
I also read about the ps command which like before I have dabbled with but the book has you learn all it's switches. ps basically just gives you a list of processes for the current user. ps -a shows ALL processes. A really neat one if pstree which gives you a tree of processes so you can see what process started what with all beginning at init.
Henry also showed me a bit about kill. As you can guess it kills a process but there are 60 variations. The default kill sends the kill command but gives the process a chance to save, kill -9 kills the program outright, kill -1 restarts the process.
Next part of the chapter is "Managing Process Priorities" and then next chapter is vi. A whole chapter dedicated to vi. I also took one of the books home but I'll have it back tomorrow.
Saturday, October 23, 2010
I also created a google doc that has a list of all the phobias we used for our hostnames. At the moment I don't see the doc being very useful since if you need to add or change a phobia you have to jump into the dhcpd.conf anyways so everyone will see your changes. Of course documentation outside of the config is nice though. I'm hoping to add to it (maybe MAC?) so that when people need something one person will be like "Hey guys let's just consult Steve's Google Doc" and then the other guy will be like "Yeah!" and then high fives are issued.
Lastly started reading on fdisk in the LPIC. One thing I take issue with this whole certification is you're left without docs. Now I realize that this occurs with every test but it's still something that annoys me. When I first used fdisk I never knew how to use it but the man pages helped me out. With LPIC you're not just expected to know what the command does but you have to know what a certain parameter does or what you need. I can understand if they ask you how to do something common like create a tar.gz which you should know by heart now but Henry and I were looking at the man pages for a command (can't remember which one) and whoever made it must have had an evil sense of humor. There were six parameters that triggered different results BUT the way they were issued was the next parameter had another t. For example, sudo makemasandwich -t would tell you the time when making the sandwich, -tt would add some mayonnaise, -ttt would get the newspaper for you and compliment you on your hair and -tttt would launch Skynet. My long complaint is it's unrealistic to expect someone to remember this. People remember what they use often and that's it. So while I may learn this stuff now if I don't use it often it's a waste of time. I know that this won't get me out of doing the work but it's nice to rant. Whether the LPIC forces me to learn this kind of stuff will be seen.
Monday, October 18, 2010
So for this week we're going to work on tcpdump and the rest is to be determined. We have to wait on the Jabber server patches according to Jeff.
About LPIC, I still have plenty of studying to do with not so much time.
Thursday, October 14, 2010
Monday, October 11, 2010
Ok more. The server is running but the docs for XS aren't good at all so we didn't really know what to do trying to set it up. According to Henry (he did this) the server gets connections from the computers but nothing happens afterward. By tomorrow I hope we can get this done.
Monday, October 4, 2010
Friday, October 1, 2010
Here's a more verbose version.
Thursday, September 30, 2010
Now what is this of Phobias you ask? Well we decided to make every computer's hostname a phobia. You can thank The Phobia List for the phobias.
Apparently Firefox thinks my entire blog post is spelled incorrectly. Now I can't tell if something is incorrect D:
Friday, September 24, 2010
I will also work on a server but I'm not sure how that will work out at the moment. Yup.
Monday, September 20, 2010
Also LPIC. I guess I'll start reading the book. I haven't actually read it yet but it thankfully comes with a .pdf so I can read it at home. I'll try and find a test online so I can see my current abilities. Hopefully I'll be adequate.
Thursday, September 16, 2010
Another thing to note. I think we ought to compile a list of packages for the LTSP server and Jeff can install them after school.
Monday, September 13, 2010
Friday, June 18, 2010
Thursday, June 10, 2010
Friday, June 4, 2010
Tuesday, May 25, 2010
So there would be two servers on the network (you could run it all one three or one if you want things to be slow). One server would have Kerberos and LDAP. Every client would also have the Kerberos client installed. On the KL server (see the acronym there?) clients would authenticate using Kerberos. Once authenticated LDAP would point to the NFS server where then the client would mount the user's home directory, or whatever you want. Here's a nice article (written for Red Hat) that shows how to create a Kerberos, LDAP, NFS system.
One thing is I don't know what kind of budget Senior jelkner (yes jelkner) has or what kind of hardware would be necessary. I assume for the KL server you wouldn't need a powerful machine but mounting the home directory of everyone in the class would be taxing on the NFS server and bandwidth hungry.
Wednesday, May 19, 2010
And today I decided against it since it seems my computer is the only one out of sync for some reason. Gonna fix that and if the need arises I can use IPCop for synced time.
This week hasn't actually been very productive. I've been just reviewing the book since the SSO isn't moving forward, yet. Waiting on the exam date and that's it basically. More review of the book next week. How's about a network related comic
You'd better have laughed, otherwise I don't know what you're doing here.
Sunday, May 16, 2010
The last chapter discussed management of network documentation. So let's say you take a new job and the guy you just took over managed THE INTERNET. Well unfortunately for you he didn't document anything thing like VLAN's, hardware, addresses or any of that stuff. Now you have to go through the network and figure it out for yourself and the internet is pretty big... So by doing the guy after you and yourself a favor by documenting everything nobody will be left with large headaches. Some things it mentioned to document but I never realized is baseline stats of servers so you would measure let's say the load on the CPU, RAM and harddisk and then for future reference if the numbers have changed you know that something is wrong.
Optimizing your network. Assuming you run a big network you'll have a lot of different traffic moving through. You wouldn't want people playing video games getting priority over people who are making calls over VOIP. By using QoS (Quality of Service) you determine what packets have a high priority and those that don't. So naturally VOIP would be high on the list. Videos would probably somewhere low so in case of high traffic situations video packets may be dropped. For web-hosting you may want to use load balancing so when millions of people are accessing your website they aren't all punishing one server and instead are spread out over all your web servers. Lastly you want fault-tolerance so if and when a server or hard drive fails customers can still get access to their data.
Something I noticed while reading other peoples blogs, that's what I do at night sitting in front of the glare of the monitor anyways, I read it in their voices. Voices in my head! Also free Portal if I didn't already mention it. Which I did.
Wednesday, May 12, 2010
Go to the IPCop router homepage and login
On the top go to Services then Advanced Proxy
Scroll down to Network Based Access Control
Under banned I.P. address enter the I.P. you want to restrict access and then scroll down and press Save and Restart.
Here is the I.P. chart. All the desktop I.P. address are up to date.
Note: the three laptop I.P. addresses are (from right left) 117, 128 and 124.
Friday, April 30, 2010
So right now I'm reading about policies and regulations. Policies are basically what you do under certain circumstances like when a user is locked out of an account, a hacker breaks into your network or when a gia... nevermind. Procedures are procedures which you do when a policy comes into effect. Regulations are rules imposed by guvamnets and other organizations that your company must follow if you don't want to get hauled off to jail.
So this post has been sitting in my edit post section for a bit. Oh well here's some more stuff.
I went back to subnetting and I do understand it better than I did before, no thanks to the book BUT thanks to Ralph Becker's IP Address Subnetting Tutorial.
So an I.P. address is composed of two parts, the network address and the node address. If you have a Class A network the first octet is the network address and the last 3 the node address. A Class B network the first two octets are the network address and the last two are the node address. I hope you can guess what the Class C address is. When the node octets of the address are set to 0 you get the network address. When they're all set to 1 you get the broadcast address.
Now here is where I got caught up which is subnet masks. Mr. Elkner gave me an explanation of subnet masks and I will reiterate it for my own clarification. When you have a network address and you want more subnets than nodes you can apply a subnet mask to give yourself more subnets. So let's say you have the class B address 178.223.000.000. The first two octets are the network address. The last two are the host/node address. By applying a subnet mask you get more subnets. Everyone outside your network sees your network address but inside the network you have your own little system of subnets.
Wednesday, April 28, 2010
When something is wrong it's always the user's fault. At least in my experience. Basically the entire chapter is diagnosing problems. First you start with the simple questions when a user can't log in like is the computer on, is the caps key on, do you have more than 2 brain cells? If somehow that doesn't work then you have to haul your arse down to the user and try things out for yourself. If it's hardware replace it, if it's software re-install it.
Now if after doing your magic the workstation still doesn't work and trying the user's login from another workstation doesn't work either you has a problem with your segment. Check the server for user permissions and if that isn't the problem have fun. (Just so you know I read the chapter, write up what I read and then re read certain parts to make sure I got the right info down.)
So if it's not the server then you have to check the cabling for things like crosstalk where to cables are bleeding onto each other, attenuation where signal is degrading over distances, collisions although that shouldn't happen in this day and age, electromagnetic interference and it could just be a bad cable.
The next part discusses troubleshooting when you have a wireless network and then the next next part of the chapter gives you steps to take in solving network problems. Yay.
Friday, April 23, 2010
So back to what I'm learning. Certifier, checks to make sure your network follows standards, costs a lot of money. Time-Domain REFLECTOMETER! It sends a signal down the a copper wire and if there's any interruption in the signal some of it will reflect back to the TDR. This allows you to check like speed of the wire, how much lost and cable length. Optical Time-Domain REFLECTOMETER performs the same function as the TDR except it's meant for fiber cables so instead of electric pulses it uses light and instead of measuring a response it measures the amount of scattered light. NEW PARAGRAPH.
You all probably know what a multimeter is. It just measures voltage, current and resistance. A Toner Probe is a somewhat nifty device where you connect one probe to the end of a wire and then using the other probe you can find that same wire in a bundle of wires since it listens for the tone.
That was a bit of a boring post but don't worry! I have something else in store!.
Thursday, April 22, 2010
A wire-map tester is one of the most basic cable testers you can buy. It just checks that the wires in a twisted-pair are in their correct places. It can also check for broken or unconnected wires. Surprisingly this basic tester starts at around 100 dollars.
A protocol analyzes, wait for it, protocols! They come in hardware and software forms. It allows you to troubleshoot problems on a network, doesn't really explain how..., gather traffic info, find unused protocols to remove from your network and traffic generating for penetration testing. And that's that for today.
Thursday, April 15, 2010
Hosts is a file in both windows and linux operating systems that provides host name to I.P. translation. This is useless for the average user and would be annoying to mess with on multiple computers but if it's just one computer you could use it to redirect to another webpage.
All the other stuff in the chapter like NetBIOS takes place on Windows so I can't try it out here.
Thrilling post wasn't it?
Monday, April 12, 2010
tracert or traceroute in linux traces the route to the remote device. Har har. More than that it lists every DNS and I.P. it takes to the receiver including the time it takes between hops.
ipconfig (ifconfig in linux) is something I used a lot before. Ifconfig lists everything about the current machines network configuration like it's I.P., DNS, default gateway, MAC addresses and all that good stuff.
ping. You know what that is. Yes you do. Ok fine I'll explain it. Ping just sends an ICMP packet to a host to make sure it's reachable. You can set different parameters like how many echo requests, force IPV6 yadda yadda.
More commands soon...
Friday, April 9, 2010
Frame Relay is a type of WAN connection based on packet switching. Packet switching basically means sending packets through different paths. It operates on virtual circuits where each client has their own allocated bandwidth. When you send data you have the CIR and the Access Rate. The CIR determines how much data is sent before it might be dropped and the Access Rate well... it's the Access Rate aka bandwidth. Back to virtual circuits they're just like a physical on except virtual so your data is moving across a large infrastructure that it never sees because it looks like it's own circuit. There are two types of virtual circuits. Permanent and switched which is like a leased phone line. The permanent is always in place while the switched is like when you make a phone call the connection is established and then dropped when the call or connection is through.
That's just one of the WAN types I read about but I'd rather not regurgitate everything I just read.
Gonna try and fix my dad's grandfather clock this weekend. I MUST HEAR THAT WESTMINSTER CHIME!
You gotta skip to the 28 second mark...
Monday, April 5, 2010
Network+ exam... To be honest I could have probably been ready by now but last quarter I just slowed down and then sped up again. Of course I'm still going to be reading the Net+ book (which I can't link) using Wikipedia for obscure things and doing the practice exams. We should talk about getting a voucher for the Net+ exam when you come back. So I'll take the exam when I can which I hope can be soon.
Right after I take the exam which is TBD I assume I'll start helping Henry or something of the sort. There won't be enough time to work out a full project especially if I take the exam late. If I get the date for the exam I could make a timeline but right now I can't really see what I'd be doing.
If I don't have a lot of time left in the quarter after I take the exam I may try programming again for the summer. I'm still keeping my options open for a career.
Thursday, March 25, 2010
Leased Line is a point-to-point connection. It is a permanent line over a long distance.
Circuit Switching is used for telephones and can be used for data as in dial-up. You only pay for the time you use not the data since you have to open up a connection.
Packet Switching is like a LAN where data sent over a half-duplex connection only one person is sending data at once. Packet Switching is basically on a large scale, so data is sent in bursts. It's not that good since you usually share it with other companies and if you need continuous connection it won't do you any good at all.
So have a happy spring break blah blah gonna go to sleep.
Wednesday, March 24, 2010
An HTTP proxy is the kind we all know and love. The way it works is a client is configured to sent all HTTP requests to the proxy so when a client accesses a website the request is sent to the proxy and then returns the website to the original sender. This can be useful when you need to get around restrictions like region or network based. An HTTP proxy can also be configured to cache web pages so bandwith isn't wasted on frequently requests web pages. Pretty much everything said applies to any kind of proxy like an FTP proxy.
Monday, March 22, 2010
Friday, March 19, 2010
Thursday, March 18, 2010
My brother has his own XO and will be keeping his own blog. We're both running the same OS, same firmware, both freshly installed and yet we seem to have different problems. One thing I want to know is if you don't want anyone else seeing this stuff so we should make everything private or if you don't care.
Wednesday, March 17, 2010
Ok now for the real stuffs. RADIUS. A while back we were considering having any wireless device authenticate itself with a username and password and be presented with a captive portal. That pretty much went kaput since it wasn't really necessary, and WPA-2 suits us fine. Anyway RADIUS is basically a way of authenticating users and giving them restricted access to resources. Kerberos is an authentication protocol that can be used on top of RADIUS. I mention Kerberos since it is used for authentication and everyone has heard of it even if they don't know what it means. Kerberos is also meant for a regular corporate network versus RADIUS which is used by ISPs to allow authentication of their users anywhere.
WeDo post in a bit...
Thursday, March 11, 2010
I left off last week with some Wi-Fi related things. The next part of the chapter is mostly hardware. In a purely Wi-Fi network there will be two components the WAP (Wireless Access Point) and a wireless NIC. You can have a wired and wireless router. A WAP will have either Omni or Yagi antennas. An omni directional antenna transmits all over the place while a Yagi antenna transmits in one direction but has greater distance than an omni antenna since it focuses all its power in one direction.
Onto networks! In a small network instead of buying a WAP you can have all your NICs operate in ad-hoc mode where each device communicates directly to each other instead through a WAP although this isn't very good since a WAP is cheap and it's hard to organize this kind of network. The other type involves a WAP which is basically like a wired network except wireless.
The cool thing about wireless networks is you can obviously move around in them since your device is wireless but you can blanked areas with WAPs so that you can move around freely and the network is fault tolerant since they will overlap each other to an extent. Unfortunately for a couple pages the book discusses how to set up a wireless connection and WAP in Windows. Not that I hate Windows (I use it more than Linux...) the book should be discussing the concepts and I would hope someone reading the book would know how to connect to a wireless network off the bat. Anyways...
The next part discusses wireless security which I will talk about next week after the super secret thing. Oh yes the super secret thing involves Legos.
Friday, March 5, 2010
Tuesday I stayed after school with Henry to check on the other 2 of 8 servers we received last week. One of the servers had 2 borked fans of 4 and the second one was fine. Henry did the server install since he had a copy of the desktop release and I left before he got the server one.
Wednesday. READ READ READ READ SLASHDOT READ READ READ READ READ READ READ READ READ READ READ READ.
Thursday I read some more about wireless standards. The chapter discusses the different 802.11 standards with the main ones being 802.11, 802.11a, 802.11b, 802.11g and 802.11n. So within the U.S. of A, Europe and everywhere else the 2.4GHz and 5GHz ranges contain channels which are open to the public so we may enjoy creating our own wireless network. As you can guess 802.11 was the first standard ratified. The more important ones are the b, g and n although b isn't as important anymore which I will explain.
So b and g both operate on the 2.4GHz range. b can give you a maximum of 11Mbps. The reason it has such low bandwith is because it uses the Ethernet based collision detection CSMA/CA. Basically each packet sent requires an acknowledgment which consumes resources.
As stated previously g also operates in the 2.4GHz range and has a maximum data rate of 54Mbps. It uses some magic called Direct Sequence Spread Spectrum that is further into the chapter. The cool the about g is that g devices are backwards compatible with b devices. The bad thing is a b device only works when the other device is in b mode so even if you have 5 g devices and 1 b device connecting to some b/g AP ALL the devices will be limited to 11Mbps.
n is a somewhat recently ratified standard that operates in both the 2.4 and 5 GHz ranges. The biggest thing about n is MIMO is implemented in it which allows a AP to have up to 8 antennas for Multiple-Input Multiple-Output (MIMO).
I'll be back with more wireless standard goodness for next week!
Thursday, February 25, 2010
Thursday, February 18, 2010
Also I lied about finishing the chart sort of. Apparently there is a problem with either inkscape or the .svg file format where some text boxes appear as black boxes. The great part about this problem is I have no idea how to delete the boxes since the normal method of selecting one doesn't work. So, here's is in it's black box covered glory. Cool beans.
OH WAIT. I forgot to explain what and .svg file is in the first place. Basically it's a vector graphic image which means it scales to whatever size so if you wanted to show a smiley face on a giant superbowl screen in all it's smiley glory it wouldn't blur at all since it's based on algorithms rather than the position of each individual picture. I think.
Thursday, February 4, 2010
Friday, January 29, 2010
Thursday, January 28, 2010
A hub and switch are like the same thing except they aren't. Both can segment networks but a switch can basically do it better. There really isn't a reason to use a hub over a switch unless you don't have the monies or you already have a bunch of hubs but even then one switch would be good. When the hub receives data it bombards every port with the data and those computers that weren't meant to recieve the data get rid of it. It's a waste of bandwidth but there is no processing involved which isn't really a surprise when you just throw crap at everyone. A switch is basically the opposite. It bombards each port so it can discover which MAC is assigned to each port so then later on it can just send the data to that specific port without wasting bandwidth.
I'll make another post tomorrow.
Wednesday, January 20, 2010
Guess what I'll be doing next quarter? Networking! I'm am hopeful and completely very mostly somewhat slightly confident that I will be ready for the Net+ exam by the beginning of 4th quarter. I haven't been reading the book in order but I would say I'm 60 to 70 percent of the way there as long as the chapters don't get any harder or denser. So, yeah.
Tuesday, January 12, 2010
First thing of the quarter was getting the whitelist ready which feels like a million years ago. It taught me how painful it can be if you don't read the documentation. I "learned" the OSI model as in I understand how it works, encapsulation and what not. I still need to memorize the layers. I learned about all the fun and exciting cables like Fiber, Cat and Dog. (Didya see the joke in there? Cat and Dog? Geddit? Shut up). I now know how to convert number to binary to hex. I also learned a pretty couple minor things like using SCP but that's not really worth listing. So that's it.
As you can guess my next quarter goal will be to continue working with Net+.
Strange how I can write a page on one topic and yet when making a review I can only come up with one paragraph.
Friday, January 8, 2010
Over the break I ate a lot, played video games, researched LDAP and had a small epiphany, although that's for another day. I searched the internet trying to find a guide on how to setup an LDAP server. There is a lot of info out there but it's all gibberish to someone new to it like me. I guess they expect you to have some prior knowledge which means nobody ever makes some good documentation. I did find a decent guide on the Ubuntu website which guides you through making an LDAP server which is very nice but even if I did set up the server when Mr. Elkner comes to me and says he wants something not part of the guide or something breaks I'll be screwed so I would need to learn more about LDAP.
So during the course of the week I learned how to convert numbers to binary, binary to hex blah blah. It actually isn't hard. The only problem is it's somewhat time consuming. I had to learn about it since hex relates to MAC addresses and binary since IP address are based on binary and so are subnets. Subnetting is probably one of the most important things you need in a large network in my opinion. I would go into a long winded explanation on why it's important but I have yet to fully understand it. Basically you can't just physically set up your network without ignoring subnetting. Once I finish the chapter and know what I'm talking about I'll make a post on it.
I know I'm forgetting something but I can't remember right now and according to some study which I can't remember where I read it said that trying hard to remember something decreases your chances of remembering what you forgot. So don't think too hard about what you forgot or you'll forget it.
Also Chuck season 3 starts this Sunday but you already knew that.