Journal of networking technology and computer science-ISSN 1925-9948: "Aw, Snap!" "OH NOES" "host dead' and other phrase...: X-abcomputer is not a typewriter! Just a little appeal: When a program dumps core, and offers you the chance to send the data to the develo...
15 November 2011
13 November 2011
"Aw, Snap!" "OH NOES" "host dead' and other phrases
X-abcomputer is not a typewriter!
Just a little appeal: When a program dumps core, and offers you the chance to send the data to the developers; please do so. It helps improve the product, and not doing so is "Considered Harmful" Your crash reports are helpful to the people who write the programs. Do your part and send the info, you probably don't have anything to hide anyways!
"Aw, Snap!" "OH NOES" "host dead' and other phrases by DD49net is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Canada License.
Permissions beyond the scope of this license may be available at http://network-computer-info.blogspot.com/p/about.html.
Just a little appeal: When a program dumps core, and offers you the chance to send the data to the developers; please do so. It helps improve the product, and not doing so is "Considered Harmful" Your crash reports are helpful to the people who write the programs. Do your part and send the info, you probably don't have anything to hide anyways!
"Aw, Snap!" "OH NOES" "host dead' and other phrases by DD49net is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Canada License.
Permissions beyond the scope of this license may be available at http://network-computer-info.blogspot.com/p/about.html.
22 August 2011
Programming books...Lacking in roubustness
So, as I've been reading various various books on programming, I've come to notice various things.
One is that many are very cryptic. They seem to assume one already knows the fine points of the language in question. If you already knew the language, why would you even bother reading a book on it?
Another is the way the books break down the language. They break it down instruction by instruction, without really doing a good job tying together all the pieces that are required to write a functional program. For example, you must be able to use arrays, variables, operators and input/output all in the same work in order to write a real world program, but the books handle these all as discreet items.
Finally, there is a lack of holistic approach. Very few books touch on the underlying principals such as compact code, robustness, portability, functionality, optimisation and other points that make a good piece of code a great piece of code. A good book on this is Eric S. Raymond's
'The Art of UNIX Programming' but it does teach one code, it only teaches the broader principals.
Programming books...Lacking in roubustness by DD-49 network is licensed under a Creative Commons Attribution-ShareAlike 2.5 Canada License.
Based on a work at network-computer-info.blogspot.com.
These are just some surface observations I have made of technical publications that I wished to share.
One is that many are very cryptic. They seem to assume one already knows the fine points of the language in question. If you already knew the language, why would you even bother reading a book on it?
Another is the way the books break down the language. They break it down instruction by instruction, without really doing a good job tying together all the pieces that are required to write a functional program. For example, you must be able to use arrays, variables, operators and input/output all in the same work in order to write a real world program, but the books handle these all as discreet items.
Finally, there is a lack of holistic approach. Very few books touch on the underlying principals such as compact code, robustness, portability, functionality, optimisation and other points that make a good piece of code a great piece of code. A good book on this is Eric S. Raymond's
'The Art of UNIX Programming' but it does teach one code, it only teaches the broader principals.
Programming books...Lacking in roubustness by DD-49 network is licensed under a Creative Commons Attribution-ShareAlike 2.5 Canada License.
Based on a work at network-computer-info.blogspot.com.
These are just some surface observations I have made of technical publications that I wished to share.
02 July 2011
Before you throw out your old PC...
Consider some of the following options.
Reuse it in your home or office as network storage device/file server to keep shared use files and large files like videos on. It's not that hard to set-up a file server like that.
Install a light (in terms of system resources) linux distribution and use it as work computer for things like word processing, spreadsheets, web design or programming/development.
Use it with Linux as a learning platform to learn more about computer technology, go play around in BASH, learn how to use the command line, learn how to set-up routing, set-up a web server, learn some programming. Have fun and learn skills that can be useful at work and avoid you needing to pay a computer technician in the future.
Strip it down for parts- That DVD-RW drive is still good, so is the power supply, hard drive and PCI cards. Use them in your new PC or keep them as spares. Bring the stripped out carcass to a household hazardous waste depot for environmentally friendly disposal.
Give it someone who is less able to get one themselves, be it a child in the family, an senior who just wants to surf the web and keep busy, or someone living in poverty who your gift might make the difference to learning skills and finding a job, or staying in poverty.
Donate to a project like freegeek, who will refurbish the computer, dispose of any electronic waste in a safe way, and sell the refurbished PC for a low price to enable access to technology for everyone. They'll also 'nuke' your hard drive to destroy any data you had to protect your privacy.
Donate it to a charity store like goodwill, where it will be sold cheaply and where the revenue will do some good for the world.
At the very minimum, bring it a hazardous waste depot, there is a lot of lead and such in a PC and it should not go right into a landfill.
We hope you will consider these options next time you have an 'obsoleted' PC to deal with.
Before you throw out your old PC... by DD-49 network is licensed under a Creative Commons Attribution-ShareAlike 2.5 Canada License.
Based on a work at network-computer-info.blogspot.com.
Reuse it in your home or office as network storage device/file server to keep shared use files and large files like videos on. It's not that hard to set-up a file server like that.
Install a light (in terms of system resources) linux distribution and use it as work computer for things like word processing, spreadsheets, web design or programming/development.
Use it with Linux as a learning platform to learn more about computer technology, go play around in BASH, learn how to use the command line, learn how to set-up routing, set-up a web server, learn some programming. Have fun and learn skills that can be useful at work and avoid you needing to pay a computer technician in the future.
Strip it down for parts- That DVD-RW drive is still good, so is the power supply, hard drive and PCI cards. Use them in your new PC or keep them as spares. Bring the stripped out carcass to a household hazardous waste depot for environmentally friendly disposal.
Give it someone who is less able to get one themselves, be it a child in the family, an senior who just wants to surf the web and keep busy, or someone living in poverty who your gift might make the difference to learning skills and finding a job, or staying in poverty.
Donate to a project like freegeek, who will refurbish the computer, dispose of any electronic waste in a safe way, and sell the refurbished PC for a low price to enable access to technology for everyone. They'll also 'nuke' your hard drive to destroy any data you had to protect your privacy.
Donate it to a charity store like goodwill, where it will be sold cheaply and where the revenue will do some good for the world.
At the very minimum, bring it a hazardous waste depot, there is a lot of lead and such in a PC and it should not go right into a landfill.
We hope you will consider these options next time you have an 'obsoleted' PC to deal with.
Before you throw out your old PC... by DD-49 network is licensed under a Creative Commons Attribution-ShareAlike 2.5 Canada License.
Based on a work at network-computer-info.blogspot.com.
30 June 2011
A tip on how to possibly prolong the life of and increase the performance of your CPU
I was talking with some fellow techies today, and we where talking about maintenance or refurbishment of PCs. I raised a point about thermal creep, and thermal failure, and why I liked to, on a PC of a few years age, or one used a lot. (such as a server that is going 24/7) that I liked to pull the heatsink and CPU as part of the routine maintenance or refurbishment.
The for it originally was I noticed that the heat-sink would seem to be improperly seated and that the thermal paste was always brown and dried up. So I'd pull em, clean the CPU die and the sink surface, put on some fresh stuff and than make sure it was seated properly when I re-installed.
I've personally noticed that on computer's where I did this, they seemed to have less CPU failures and a little better performance.
I guess it makes some sense. The thermal paste does more then just transfer heat, it also acts as seat of sorts for the two surfaces, smoothing out the imperfections in the surface of each to assure a close mated bond. That close bond is ESSENTIAL to heat transfer.
So after a bit, when that heat grease dries up, you don't have the close bond any more.I'd also suppose that fresh thermal paste is a better conductor of heat then old, dried up stuff.
As we all know, a cool CPU will last longer and give better performance than an overheated one will.
I know it's a little of a pain to pull the CPU out. (or more so, to remount the heat sink) But in my opinion, it is worth it. Thermal paste is not that expensive, so be generous with it and coat the CPU die nicely.
One warning: Where the heat sink mounts directly to the CPU socket with a steel clip on plastic nibs, be careful not to shear the plastic nibs off. But with that the only caution, I do highly recommend that re-pasting your of your chip every now and then.
A tip on how to possibly prolong the life of and increase the performance of your CPU by DD-49 network is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
Based on a work at network-computer-info.blogspot.com.
The for it originally was I noticed that the heat-sink would seem to be improperly seated and that the thermal paste was always brown and dried up. So I'd pull em, clean the CPU die and the sink surface, put on some fresh stuff and than make sure it was seated properly when I re-installed.
I've personally noticed that on computer's where I did this, they seemed to have less CPU failures and a little better performance.
I guess it makes some sense. The thermal paste does more then just transfer heat, it also acts as seat of sorts for the two surfaces, smoothing out the imperfections in the surface of each to assure a close mated bond. That close bond is ESSENTIAL to heat transfer.
So after a bit, when that heat grease dries up, you don't have the close bond any more.I'd also suppose that fresh thermal paste is a better conductor of heat then old, dried up stuff.
As we all know, a cool CPU will last longer and give better performance than an overheated one will.
I know it's a little of a pain to pull the CPU out. (or more so, to remount the heat sink) But in my opinion, it is worth it. Thermal paste is not that expensive, so be generous with it and coat the CPU die nicely.
One warning: Where the heat sink mounts directly to the CPU socket with a steel clip on plastic nibs, be careful not to shear the plastic nibs off. But with that the only caution, I do highly recommend that re-pasting your of your chip every now and then.
A tip on how to possibly prolong the life of and increase the performance of your CPU by DD-49 network is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
Based on a work at network-computer-info.blogspot.com.
28 June 2011
What is an Internet exchange?
You may heard the term "Internet exchange" or simply "IX" and wondered what it is. Will I am going to write a brief answer. An Internet exchange is a building1simply put is major network that has been assigned an AS number by ARIN. They tend to be mostly Internet service providers. As for peering, that means internetworking their networks to facilitate the transfer of data between the two. (i.e.. I'm chatting with you on my ISP and its network, your on another. They have gap somehow) True peering is free, its reciprocal transfer of data. There are also IP transit companies like hurricane electric and global crossings, who charge for transmitting data, but have such a huge network, they can get away with so doing, because they can deliver data nearly anywhere on earth.
But in essence an Internet exchange aggregated all the connectivity in a region and allows the networks to share data. I will wrote on peering, IP transit and autonomous systems at a later date
22 June 2011
Bits Vs Bytes and your internet or network connection speed.
Alright, lets get to the basics, bits and bytes are both a measure of data size, however each is rather different. To differentiate the two, bits are expressed as say 34 kilobits will be 34kb. 34 kilo bytes will be expressed as 34KB. Note the capitals and the how bits are lower case and bytes are upper case.
File size on disc is always expressed in bytes, so maybe you have a song that is 3.4MB (3.4 x 1024 million bytes) in size, and you want to transfer it over your internet connection. Say, a 512kbps (512x 1000 bits...note that bits are expressed as 1000, bytes in 1024) ADSL line. You calculate at half a mb per second, it should take 6-7 seconds.
Then you rage out when you see your connection hitting a wall at 62KBPS. You call your ISP and fume and throw venom at the costumer service guy.
Guess what?! Network connection speeds are always expressed in bits per second! not in bytes per second! To convert kbps to KBPS use the following [Kilobits per second times 1000) divided by 8)) divided 1024 ]
512 times 1000 = 512000. 512000 divided by 8 = 64000. 64000 divided by 1024 = 62.5. Or you can make it easier and use [kbps times 0.1220703125 = KBPS]
512 times 0.1220703125 = 62.5.
Thus your upper limit on data transfer speeds is actually is 62.5Kilobytes per second. Not 512 kilobytes per second. Thats your upper limit! depending on how far you from the telco's central office, how good your local loop of copper wire is, if your ISP or telco does throttling or traffic shaping, and your network over head. (things like unroutable packets pinging around til their TTL is up, and Internet control message protocol packets) You will can expect your rate to be at least 20% lower then your maximum calculated transfer speed...of course if your ISP is nice, you may exceed it if they are not strict on throttling it.
The kind of tricky thing is, network connection speeds are kbps/mbps. Files sizes are in KB/MB..and when you see a download or upload rate...its in KBPS or MBPS, because thats how file size is measured. But that can cause you confusion if you don't know that and are paying for 512kbps and get upset that you can't exceed 62.5KBPS...just remember connection speed= bits per second, download rate, bytes per second.
Hopefully my above explanation has cleared up that common source of computing/networking frustration.
Another note is, if you are using a hub/switch/router to share your connection, the total available bandwidth is shared with the other computers. So if you are downloading a movie while your room-mate is streaming in audio, both of you will notice a drop in connection speed as it is divided amongst you.
Your rated speed is the theoretical maximum, you will generally, never be able to hit that speed unless your inside the telco's central office or the internet exchange where your ISP peers off...not unless your ISP gives you some wiggle room by setting your maximum higher then advertised so you can hit the advertised speed.
We here at interconnect hope this article has cleared some confusion, as we get asked about this topic a lot.
kilobits vs kilobytes by DD-49 network is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
Based on a work at network-computer-info.blogspot.com.
File size on disc is always expressed in bytes, so maybe you have a song that is 3.4MB (3.4 x 1024 million bytes) in size, and you want to transfer it over your internet connection. Say, a 512kbps (512x 1000 bits...note that bits are expressed as 1000, bytes in 1024) ADSL line. You calculate at half a mb per second, it should take 6-7 seconds.
Then you rage out when you see your connection hitting a wall at 62KBPS. You call your ISP and fume and throw venom at the costumer service guy.
Guess what?! Network connection speeds are always expressed in bits per second! not in bytes per second! To convert kbps to KBPS use the following [Kilobits per second times 1000) divided by 8)) divided 1024 ]
512 times 1000 = 512000. 512000 divided by 8 = 64000. 64000 divided by 1024 = 62.5. Or you can make it easier and use [kbps times 0.1220703125 = KBPS]
512 times 0.1220703125 = 62.5.
Thus your upper limit on data transfer speeds is actually is 62.5Kilobytes per second. Not 512 kilobytes per second. Thats your upper limit! depending on how far you from the telco's central office, how good your local loop of copper wire is, if your ISP or telco does throttling or traffic shaping, and your network over head. (things like unroutable packets pinging around til their TTL is up, and Internet control message protocol packets) You will can expect your rate to be at least 20% lower then your maximum calculated transfer speed...of course if your ISP is nice, you may exceed it if they are not strict on throttling it.
The kind of tricky thing is, network connection speeds are kbps/mbps. Files sizes are in KB/MB..and when you see a download or upload rate...its in KBPS or MBPS, because thats how file size is measured. But that can cause you confusion if you don't know that and are paying for 512kbps and get upset that you can't exceed 62.5KBPS...just remember connection speed= bits per second, download rate, bytes per second.
Hopefully my above explanation has cleared up that common source of computing/networking frustration.
Another note is, if you are using a hub/switch/router to share your connection, the total available bandwidth is shared with the other computers. So if you are downloading a movie while your room-mate is streaming in audio, both of you will notice a drop in connection speed as it is divided amongst you.
Your rated speed is the theoretical maximum, you will generally, never be able to hit that speed unless your inside the telco's central office or the internet exchange where your ISP peers off...not unless your ISP gives you some wiggle room by setting your maximum higher then advertised so you can hit the advertised speed.
We here at interconnect hope this article has cleared some confusion, as we get asked about this topic a lot.
kilobits vs kilobytes by DD-49 network is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
Based on a work at network-computer-info.blogspot.com.
18 June 2011
bridging vs routing modems
Some of you out there may be wondering what the difference between a bridging modem and a routing modem is.
I am speaking of DSL modems in this article, for clarification.
A bridging modem acts as a network BRIDGE like its name implies. That is to say, it bridges the difference in protocols and routing policies used on your network with the ones used on your Internet Service Providers Network. It will only allow you to connect a single computer to the other network unless you have a router in place. However, it allows you more flexibility in internal networking, as you may more easily set up multiple routers and subnets. This type of modem is best reserved for the advanced or business user or if your ISP requires bridging encapsulation.
A routing modem is a modem with a router built in. It acts in the manner of an edge of service router. (on much smaller scale!) and acts as a network gateway to sorts out the differences between your network and your ISP's network by running some routing protocol designed to do so. (typically IGREP- Interior Gate routing protocol) to complement your ISP's running of typically Exterior Gateway Routing Protocol. It also handles connecting more then one device via a hub or switch by using Network Address Translation and Port Forwarding.
This is typically your most commonly used consumer modem, and the type I'd recommend if you just want to plug in and go online.
Both have their place however, and you'll generally know which kind you need.
bridging vs routing modems by Dylan DiSalle is licensed under a Creative Commons Attribution-NoDerivs 2.5 Canada License.
Based on a work at network-computer-info.blogspot.com
I am speaking of DSL modems in this article, for clarification.
A bridging modem acts as a network BRIDGE like its name implies. That is to say, it bridges the difference in protocols and routing policies used on your network with the ones used on your Internet Service Providers Network. It will only allow you to connect a single computer to the other network unless you have a router in place. However, it allows you more flexibility in internal networking, as you may more easily set up multiple routers and subnets. This type of modem is best reserved for the advanced or business user or if your ISP requires bridging encapsulation.
A routing modem is a modem with a router built in. It acts in the manner of an edge of service router. (on much smaller scale!) and acts as a network gateway to sorts out the differences between your network and your ISP's network by running some routing protocol designed to do so. (typically IGREP- Interior Gate routing protocol) to complement your ISP's running of typically Exterior Gateway Routing Protocol. It also handles connecting more then one device via a hub or switch by using Network Address Translation and Port Forwarding.
This is typically your most commonly used consumer modem, and the type I'd recommend if you just want to plug in and go online.
Both have their place however, and you'll generally know which kind you need.
bridging vs routing modems by Dylan DiSalle is licensed under a Creative Commons Attribution-NoDerivs 2.5 Canada License.
Based on a work at network-computer-info.blogspot.com
15 June 2011
When Ironworking met I.T.
Today, one of our techs, who has a diploma in metalworking, found a unique solution to mounting a hard drive rack into a proprietary Dell 5 1/2 inch bay. This particular machine was destined to be a server and was to have 3 terabyte 3.5'' drives mounted. The rack was blocked by two protrusions from the case, and had means of being secured to the chassis.
Our tech whipped out his multi tool, used skilled metalworking techniques to bend back the protrusions right at their base, placed the hard drive rack into the chassis. To secure the rack to the chassis, he used the same protrusions, bending them back and right over until they where flush with the bottom of the hard disk rack. That provided a solid mounting base for the rack and required no holes drilled or reamed and made the 5.5 inch bay usable for the 3.5 inch drives.
Truly an 'outside the box' solution, to fall back on iron working techniques for I.T. tasks, but also a great hardware hack that solved the issue in the minimum of time, no expense and with ease.
The idea we're trying to get across here is to always look at problems from other angles; very often one can find a solution from an 'non-related' field.
Our tech whipped out his multi tool, used skilled metalworking techniques to bend back the protrusions right at their base, placed the hard drive rack into the chassis. To secure the rack to the chassis, he used the same protrusions, bending them back and right over until they where flush with the bottom of the hard disk rack. That provided a solid mounting base for the rack and required no holes drilled or reamed and made the 5.5 inch bay usable for the 3.5 inch drives.
Truly an 'outside the box' solution, to fall back on iron working techniques for I.T. tasks, but also a great hardware hack that solved the issue in the minimum of time, no expense and with ease.
The idea we're trying to get across here is to always look at problems from other angles; very often one can find a solution from an 'non-related' field.
14 June 2011
A little reminder about something that left me connectless
So, I had gotten a new ADSL modem and was excited to install in. So I quickly pull the phone wire, the cat 6 that goes to my switch and the power and swap in the new one.
Silly me! I'm using point to point over Ethernet (PPPOE) and I did not have my password around. I tried the old modem, but had forgotten the password due to being unplugged.
I was screwed. I use an independent Internet Service provider, so no tech support to call.
Then I remembered I had the connection details in my email. So off to the Internet Cafe it was; to search my mail for the password. I did find it and set up my modem.One of these to be exact- TP-Link TD-8616 - DSL modem - external - Fast Ethernet - 24 Mbps
.
Now I keep my PPPOE password in my wallet. (No not with my user-name, making it useless to anyone else) and I recommend that anyone keeps a piece of information needed to "bootstrap" a system written and handy, a lesson well learned.
I figured I'd share that tale as I install gentoo on a box...doing the tarball download.
Silly me! I'm using point to point over Ethernet (PPPOE) and I did not have my password around. I tried the old modem, but had forgotten the password due to being unplugged.
I was screwed. I use an independent Internet Service provider, so no tech support to call.
Then I remembered I had the connection details in my email. So off to the Internet Cafe it was; to search my mail for the password. I did find it and set up my modem.One of these to be exact- TP-Link TD-8616 - DSL modem - external - Fast Ethernet - 24 Mbps
.Now I keep my PPPOE password in my wallet. (No not with my user-name, making it useless to anyone else) and I recommend that anyone keeps a piece of information needed to "bootstrap" a system written and handy, a lesson well learned.
I figured I'd share that tale as I install gentoo on a box...doing the tarball download.
10 June 2011
networking how to and info-intro to network tech: apt-cache: how to use
networking how to and info-intro to network tech: apt-cache: how to use: "So, today distro. I'm going to write to appeal to our Debian/Ubuntu/related readers. In case you where unaware, you can download whole rep..."
apt-cache: how to use
So, today . I'm going to write to appeal to our Debian/Ubuntu/related distro using readers.
In case you where unaware, you can download whole repository of packages for your Doing greatly speeds up updating, and if your in the business of making computers. (for example free-geek) having apt-cache set up will save you both tonnes of time and bandwidth, and thus money. And its real easy to do. Install the OS of choice (i.e. to cache ubuntu, install ubuntu server
A open a console and type the following.
One of the great things about this, is you can put old, 'obsolete' Pentium III back into use, as an FTP file server does not require a lot of systems resources, which is another bonus, as you help protect the environment by avoiding electronic waste.
In case you where unaware, you can download whole repository of packages for your Doing greatly speeds up updating, and if your in the business of making computers. (for example free-geek) having apt-cache set up will save you both tonnes of time and bandwidth, and thus money. And its real easy to do. Install the OS of choice (i.e. to cache ubuntu, install ubuntu server
A open a console and type the following.
sudo apt-get install apt-cache(then type yes to the fact its going to download about 70 gigs of files)
sudo apt-cache
One of the great things about this, is you can put old, 'obsolete' Pentium III back into use, as an FTP file server does not require a lot of systems resources, which is another bonus, as you help protect the environment by avoiding electronic waste.
09 June 2011
A small networking glitch that put my net off-line.
So, I was I just trying to add a route to my routing table...no big deal. But after I did so, I was unable to bring my internal network online. I scanned my settings and did not see anything wrong VPI/VCI where correct, gateway was correct.
I was truly confused. Then finally, I looked at the PPPoE settings...some how a single letter in my user name was dropped! No wonder I couldn't connect huh? So I corrected the letter and saved my settings. I waited 20 minutes. Still no connection!
After logging back into my ADSL modem, I seen it had not saved my PPPoE user name correctly!
I decided to correct it again. This time, it finally took.
The message here is, always check all your settings when you have a failure mode, and after you correct them, check to ensure they are genuinely corrected and saved and not discarded.
I was truly confused. Then finally, I looked at the PPPoE settings...some how a single letter in my user name was dropped! No wonder I couldn't connect huh? So I corrected the letter and saved my settings. I waited 20 minutes. Still no connection!
After logging back into my ADSL modem, I seen it had not saved my PPPoE user name correctly!
I decided to correct it again. This time, it finally took.
The message here is, always check all your settings when you have a failure mode, and after you correct them, check to ensure they are genuinely corrected and saved and not discarded.
07 June 2011
A bit on SEO
So, chances are if you own a website, you want traffic, you want visitors to your website, right? Well, most web traffic comes from search engine results, and links to your site on other sites. Today we will touch a little on search engine ranking.
The way search engines work (for the most part, they are very complex so I'll simplify) is they have a bot (an application) that visits your site, and absorbs all the content...including invisible content such as meta tags and things such as the words in the URL and the title and description of the site.
The most important thing is to write quality content, and write it using the language of your intended readers. This is very important, because when your readers are searching for information in a search engine, they will use keywords from their vocabulary and from their point of view. If your writing in a jargon filled field like information technology or medicine, and trying to appeal to people with little or no background, use common terms. Don't say something like
"RFC 950 does not specify if subnets of the same major net may or may not have different subnet masks" Try something like " When it comes to dividing up your network in smaller nets, there is no defined rule on if you can use different masks for different subnets, as per RFC 950 which covered this topic"
Follow that with a link to RFC 950 so your reader can find more detail if they wish.
Post links to pages on your site in relevant web forums. But be judicious about it. Only post something that is truly on the topic and will provide the participants with information on the subject of the discussion.
Make sure your website has working, complete link paths. That is to say, make sure every page can be found by clicking links starting on the default page and following links as click deeper into the website. This way, search engine's bots will be able to index your entire sites content and all its pages, giving it more chances to turn up on the search engine results page when someone does a search.
Submit your site to all the major search engines and web directories, and to unique, smaller ones like Active Search Results Search Engine
this gives you both the major audiences in major search engines like Google and yahoo, which are very hard to get high ranking in, as well as giving you the niche audience of smaller engines, which can be easier to obtain a high rank in.
Try to get link exchanges with websites on the same topic. This is easiest done with non commercial sites, as you are not competing for business, but even commercial sites can do it. Place advertisements on your page, not only will earn money, but they will add additional content that will give you more keywords with more variety. like this, which is a pretty cool gadget to be honest. Kindle, Wi-Fi, Graphite, 6" Display with New E Ink Pearl Technology - includes Special Offers & Sponsored Screensavers
But always remember, content is king, if your website is vapid, you will never obtain high readership. So make sure to always put informative, relevant content on every page.
Well I hope this gave people reading a bit of idea on promoting their website, and where/how to find more information. This book here is quite good.
A bit on SEO by Dylan DiSalle is licensed under a Creative Commons Attribution-NoDerivs 2.5 Canada License.
The way search engines work (for the most part, they are very complex so I'll simplify) is they have a bot (an application) that visits your site, and absorbs all the content...including invisible content such as meta tags and things such as the words in the URL and the title and description of the site.
The most important thing is to write quality content, and write it using the language of your intended readers. This is very important, because when your readers are searching for information in a search engine, they will use keywords from their vocabulary and from their point of view. If your writing in a jargon filled field like information technology or medicine, and trying to appeal to people with little or no background, use common terms. Don't say something like
"RFC 950 does not specify if subnets of the same major net may or may not have different subnet masks" Try something like " When it comes to dividing up your network in smaller nets, there is no defined rule on if you can use different masks for different subnets, as per RFC 950 which covered this topic"
Follow that with a link to RFC 950 so your reader can find more detail if they wish.
Post links to pages on your site in relevant web forums. But be judicious about it. Only post something that is truly on the topic and will provide the participants with information on the subject of the discussion.
Make sure your website has working, complete link paths. That is to say, make sure every page can be found by clicking links starting on the default page and following links as click deeper into the website. This way, search engine's bots will be able to index your entire sites content and all its pages, giving it more chances to turn up on the search engine results page when someone does a search.
Submit your site to all the major search engines and web directories, and to unique, smaller ones like Active Search Results Search Engine
this gives you both the major audiences in major search engines like Google and yahoo, which are very hard to get high ranking in, as well as giving you the niche audience of smaller engines, which can be easier to obtain a high rank in.
Try to get link exchanges with websites on the same topic. This is easiest done with non commercial sites, as you are not competing for business, but even commercial sites can do it. Place advertisements on your page, not only will earn money, but they will add additional content that will give you more keywords with more variety. like this, which is a pretty cool gadget to be honest. Kindle, Wi-Fi, Graphite, 6" Display with New E Ink Pearl Technology - includes Special Offers & Sponsored Screensavers
But always remember, content is king, if your website is vapid, you will never obtain high readership. So make sure to always put informative, relevant content on every page.
Well I hope this gave people reading a bit of idea on promoting their website, and where/how to find more information. This book here is quite good.
A bit on SEO by Dylan DiSalle is licensed under a Creative Commons Attribution-NoDerivs 2.5 Canada License.
03 June 2011
Review of Ubuntu 11.04
So I've installed Ubuntu 11.04 and played with a bit so far. While its generally the same deal as the previous version. (a user friendly yet full scale operating system) I have to say I am disappointed in the new unity desktop environment.
I personally find the unity desktop to be less user friendly then Gnome (my choice) or XFCE. It reminds of Mac OS-X with all the rolly, moving icons and strange menu set-up's. Now maybe as a linux and BSD guy, I have a bias against mac, but I've always found Mac overly complex to use. Further, all this fancy animated desktop requires something...things like RAM and processor power and a decent GPU. That to me is taking away from the essential things about linux. The fact it can generally be run on computers with very low system resources. I guess it still can, one could boot into gnome or Xterm, if gnome is heavy, Xterm and install XFCE. But I see no reason for the new desktop, Gnome was very functional, easy to use and is still my, and many of my fellow's, choice of a desktop.
Aside from that, its good, solid OS, as ubuntu always tends to be. It has a few bugs, but that's expected with any new release. Indeed, most of them have already been fixed with updates.
So overall, I think its a good solid release. I dislike unity, but hey, others might love it as a desktop, and you still get gnome installed incase you hate it. So it's hard to loose.
I personally find the unity desktop to be less user friendly then Gnome (my choice) or XFCE. It reminds of Mac OS-X with all the rolly, moving icons and strange menu set-up's. Now maybe as a linux and BSD guy, I have a bias against mac, but I've always found Mac overly complex to use. Further, all this fancy animated desktop requires something...things like RAM and processor power and a decent GPU. That to me is taking away from the essential things about linux. The fact it can generally be run on computers with very low system resources. I guess it still can, one could boot into gnome or Xterm, if gnome is heavy, Xterm and install XFCE. But I see no reason for the new desktop, Gnome was very functional, easy to use and is still my, and many of my fellow's, choice of a desktop.
Aside from that, its good, solid OS, as ubuntu always tends to be. It has a few bugs, but that's expected with any new release. Indeed, most of them have already been fixed with updates.
So overall, I think its a good solid release. I dislike unity, but hey, others might love it as a desktop, and you still get gnome installed incase you hate it. So it's hard to loose.
30 May 2011
Switchs, hubs, and routers-whats the difference?
I've noticed a lot of people mistake or misuse the terminology between switches, hubs and routers. I believe the reason for this is because quite often, a small office/home office (SOHO) router will contain a switch or a hub as well.
Lets start off with hubs. Hubs are a device that allow you to connect multiple hosts on the same network segment/subnet. Hubs are a fairly dumb device. Dumb in that they do not keep track of what traffic is coming or going from each host. Their solution is to simply broadcast all incoming packets. Broadcast on a small network being sending the packet of 255.255.255.255. i.e. sending this traffic to every host. Hubs also do no do any load balancing, they split available bandwidth amongst all ports/all connected hosts. So if you have a regular DSL line and sharing it with 16 people, you can expect the connection to work like molasses on a cold day. That said, they do make switching hubs. Later in this article I will describe switches.
A switch is somewhat like hub, in that it allows the interconnection of many hosts on a single network segment or subnet. A switch varies because unlike a hub, it keeps a table of what host is sending and receiving what traffic. For example, instead of sending the packets on all ports to 255.255.255.0, it will send them "host 16" connected to port 16 on 192.168.1.16. This causes the switch to be faster then a hub, more secure then hub (because its not broadcasting) and save internal bandwidth. (again because its not broadcasting. It also preserves outbound bandwidth by seeing what computers are transmitting and giving them bandwidth allocation, which results is better bandwidth management.
Now the fun stuff...routers. Routers, in the pure sense, are devices that read the header of the packet for its destination address and using routing tables and other routers, forwards this packet to other routers until finally it arrives at the destination network/host or the packet outlives its time to live or is dropped as unroutable. Nearly everyone has a router, as they are found at the gateways between networks, the most common and familiar one being the gateway between your Internet Service Provider and your internal Local Area Network. (even if that internal network consists of one host/computer its still considered at network and requires routing for its interconnection)
Typical SOHO routers that are embedded with DSL modems will contain in them a Dynamic host control protocol server, and facilities for Network Address translation. (I'll cover these concepts in another post) Routers tend to use a protocol like ICMP to communicate with each other, advertise their routes. (which address space they can route a packet to and how they do it) and other things that I'll cover in a post dedicated to routing. Aside from your SOHO routers, there is a polar opposite, the core router which runs on fiber optic backbone and handles 100's of megabits per second. Cisco and Juniper are well know manufactures of these types of routers. I'll close by saying, if it was not for routers, all the way from SOHO routers to core routers, the internet would simply fail. As historic note, the first router was called an "interface message processor" was as large as fridge, based on the Honeywell 516 computer and came out in 1969. It was *the* device that enabled ARPANET to work, and thus gave birth to the internet and packet switched networks in general
Lets start off with hubs. Hubs are a device that allow you to connect multiple hosts on the same network segment/subnet. Hubs are a fairly dumb device. Dumb in that they do not keep track of what traffic is coming or going from each host. Their solution is to simply broadcast all incoming packets. Broadcast on a small network being sending the packet of 255.255.255.255. i.e. sending this traffic to every host. Hubs also do no do any load balancing, they split available bandwidth amongst all ports/all connected hosts. So if you have a regular DSL line and sharing it with 16 people, you can expect the connection to work like molasses on a cold day. That said, they do make switching hubs. Later in this article I will describe switches.
A switch is somewhat like hub, in that it allows the interconnection of many hosts on a single network segment or subnet. A switch varies because unlike a hub, it keeps a table of what host is sending and receiving what traffic. For example, instead of sending the packets on all ports to 255.255.255.0, it will send them "host 16" connected to port 16 on 192.168.1.16. This causes the switch to be faster then a hub, more secure then hub (because its not broadcasting) and save internal bandwidth. (again because its not broadcasting. It also preserves outbound bandwidth by seeing what computers are transmitting and giving them bandwidth allocation, which results is better bandwidth management.
Now the fun stuff...routers. Routers, in the pure sense, are devices that read the header of the packet for its destination address and using routing tables and other routers, forwards this packet to other routers until finally it arrives at the destination network/host or the packet outlives its time to live or is dropped as unroutable. Nearly everyone has a router, as they are found at the gateways between networks, the most common and familiar one being the gateway between your Internet Service Provider and your internal Local Area Network. (even if that internal network consists of one host/computer its still considered at network and requires routing for its interconnection)
Typical SOHO routers that are embedded with DSL modems will contain in them a Dynamic host control protocol server, and facilities for Network Address translation. (I'll cover these concepts in another post) Routers tend to use a protocol like ICMP to communicate with each other, advertise their routes. (which address space they can route a packet to and how they do it) and other things that I'll cover in a post dedicated to routing. Aside from your SOHO routers, there is a polar opposite, the core router which runs on fiber optic backbone and handles 100's of megabits per second. Cisco and Juniper are well know manufactures of these types of routers. I'll close by saying, if it was not for routers, all the way from SOHO routers to core routers, the internet would simply fail. As historic note, the first router was called an "interface message processor" was as large as fridge, based on the Honeywell 516 computer and came out in 1969. It was *the* device that enabled ARPANET to work, and thus gave birth to the internet and packet switched networks in general
29 May 2011
How to obtain an IPVv6 tunnel on debian and ubuntu and windows with minial effort.
he.nethttp://gogonet.gogo6.com/page/freenet6-servicesSo, you've probably heard about IPv6. If not, I suggest reading the article at Wikipedia as short primer. Wikipedias ipv6 page In short, IPv6 is the emerging standard for Internet protocol addresses. (currently we mostly use the 32 bit IPv4 address, the all so familiar "145.67.123.74" as an example) However, the pool of IPv4 address's has run dry, and now what is coming out is the IPv6 address, which provides for 128bit addresses that look like "2001:0:53aa:64c:2c91:c387:ba5a:505f" Expressed in hexadecimal and having many more unique address's to choose from.
Okay so you want to use IPv6 but your ISP does not offer it yet. Well don't let that stop you. There services called tunnel brokers, who will give you a "tunnel" over IPv4 to carry IPv6 packets. For both Debian and Ubuntu Linux, this is an easy task.
You can go to freenet6 if you have if you have Microsoft windows, follow the on screen instructions, download their client program, and volia! you have IPv6 connectivity. If you have Debian or Ubuntu Linux, obtain the package "gogoc" either though snypatic package manager, or by using the command line "sudo apt-get install gogos" That package will automatically make a tunnel between you and their IPv6 tunnels. Another tunnel broker is Hurricane Electric Their tunnels however, require more technical know how to configure, so if your just new to this, I suggest gogo6/freenet6. However, Hurricane offers you a routed /48 block of addresses, which if you know how to use, is quite the gift... Now to check your IPv6 connectivity try using IPv6 version of google. If the page loads, congratulations, you are now part of the IPv6 collection of interconnected networks, also termed an Internet!
If it does not load or there is no obvious manner to set up a 6in4udp tunnel, try searching the Internet for the specifics of configuring your operating system to allow IPv6 connectivity.
I hope you found this post informative and useful.
Okay so you want to use IPv6 but your ISP does not offer it yet. Well don't let that stop you. There services called tunnel brokers, who will give you a "tunnel" over IPv4 to carry IPv6 packets. For both Debian and Ubuntu Linux, this is an easy task.
You can go to freenet6 if you have if you have Microsoft windows, follow the on screen instructions, download their client program, and volia! you have IPv6 connectivity. If you have Debian or Ubuntu Linux, obtain the package "gogoc" either though snypatic package manager, or by using the command line "sudo apt-get install gogos" That package will automatically make a tunnel between you and their IPv6 tunnels. Another tunnel broker is Hurricane Electric Their tunnels however, require more technical know how to configure, so if your just new to this, I suggest gogo6/freenet6. However, Hurricane offers you a routed /48 block of addresses, which if you know how to use, is quite the gift... Now to check your IPv6 connectivity try using IPv6 version of google. If the page loads, congratulations, you are now part of the IPv6 collection of interconnected networks, also termed an Internet!
If it does not load or there is no obvious manner to set up a 6in4udp tunnel, try searching the Internet for the specifics of configuring your operating system to allow IPv6 connectivity.
I hope you found this post informative and useful.
New blog
So this is my new blog. I am a networking technician who has decided to write a blog about computer sciences, networking and howto's related to computers, as well as things related to linux and BSD.
Tomorrow, I plan to write a proper technical post. but this our first post.
Tomorrow, I plan to write a proper technical post. but this our first post.
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