June 12, 2011

How to install DD-WRT onto your Linksys Cisco Home Router

Installation


Installing DD-WRT on your Linksys Cisco Router is almost as simple as installing a program onto your computer. The bad part is; if done incorrectly, you can brick your router. Installing programs on a router is known as a firmware, is done through flashing. This article will help you install DD-WRT onto your Linksys Cisco Home Router.

Identifying your Linksys Cisco Router


Visit this website to accurately identify which model your Linksys Cisco router is. Start with the brand name Cisco Linksys and go down the list.

Flashing Instructions

  1. First and foremost, you will need to download the DD-WRT file that you've identified is your model and save it to a location that you will be able to locate later to flash your router.
  2. Log into the Linksys stock firmware and choose to reset to defaults.
  3. Do a hard reset on your router (hold the reset button down for 30 seconds.) 
  4. After your router has been set to default settings and you've done a hard reset, log into your Linksys firmware by typing 192.168.1.1 into your browser.
  5. Click on the "Administration" tab
  6. Click on the "Firmware Upgrade" sub-tab.
  7. Click the "Browse" button and select the DD-WRT .bin file you downloaded and placed in a location you remembered earlier.
  8. Click the "Upgrade" button.
  9. The router will take a few minutes to upload the file and flash the firmware. You should see the power light flash multiple times, dont panic. This is normal.
  10. Once the firmware has been uploaded, a new page will open confirming that the upload was successful. Now wait about 3-5 minutes before clicking "Continue".
  11. Lastly, do another hard reset on your router.
  12. To check that you've successfully and correctly installed DD-WRT, type in 192.168.1.1 in your web browser to be able to see the DD-WRT web interface.

Reverting Back to Stock


Should you want to revert back to your router's stock firmware, you should be able to download the stock firmwaire from the Linksys's site and flash using the webgui.

Helpful Sites



June 02, 2011

At-a-Glance: OSI Model

Why should I Care About the OSI Model?

The OSI model serves as a guideline for creating and implementing network standards, devices, and internetworking schemes. Advantages of using the OSI model include the following:
  • Breaks up interrelated aspects of network operation into less-complex elements.
  • Enables companies and individual engineers to specialize design and development efforts on modular functions.
  • Provides standard interfaces for plug-and-play compatibility and multivendor integration.
  • Abstracts different layers of the network from each other to provide easier adoption of new technologies within a layer.


Develop mnemonics to help you memorize the layers and their order. Here's an example:
Please Do Not Throw Sausage Pizza Away

What Problems Need to Be Solved?

OSI layers can communicate only with the layer directly above or below it on the stack, and with its peer layer on another device. A process must be used so that information can be passed down the stack, across the network, and back up the stack on the peer device.

October 25, 2010

Quick IP Cheat Sheet used for Reference

IP Cheat Sheet

HostsNetmaskAmount of a Class C
/304255.255.255.2521/64
/298255.255.255.2481/32
/2816255.255.255.2401/16
/2732255.255.255.2241/8
/2664255.255.255.1921/4
/25128255.255.255.1281/2
/24256255.255.255.01
/23512255.255.254.02
/221024255.255.252.04
/212048255.255.248.08
/204096255.255.240.016
/198192255.255.224.032
/1816384255.255.192.064
/1732768255.255.128.0128
/1665536255.255.0.0256


June 13, 2010

How Computer Networking Can Benefit a Company

Technology is advancing at a rapid pace in today’s world. Businesses are constantly in high demands of technicians that understand the ebb and flow of information through technical devices and that is able to keep up with the growth and new innovations of demanding vendors. Computer networking is one of the many and perhaps most efficient way that information enters and leaves in the complex world of business.
Like any profession, computer networking is an art and science combined. A graphic designer can strike up a beautiful piece of artwork, but like any artist, whether it be a musician or the next Picasso, passionate artists can capture your emotions or attention. Most of the time, find themselves lost in the zone of their passion. This can be applied to computer networking as well, understanding how a business actually functions and fluctuates from day to day, month to month, and year to year is the first step in determining how to set up a network that is suitable for it. Through planning and drafting sketches, you can produce the best possible routing table and in the process, while keeping in mind how your vendor will use information, you can locate and weed out any possible conflicts or problems you may encounter in setting up this beautiful piece of network master piece. Combined with science and the results are unlimited, that’s why there are many more networking schemes to yet be discovered.
Like chemistry and biology, scientists are still researching on new medicines and cures for existing illnesses and diseases. For example, AIDS and HIV are one of the many researches taking place as one speaks. There are many computer scientists today, researching and developing new innovations in the lab and then test running them on current existing businesses to gain feedback and insights on the next big networking scheme. When implemented correctly, businesses can function properly with information being delivered on time, efficiently, and consistently; most definitely contributing to the success of a business and at the same time, giving them the upper hand in competition. We all know
that when things run smoothly, we can channel our focus on something else; in this case, the ROI of a business. So not only does efficient networking contribute to a business success, it allows it to direct its focus elsewhere, for example; push on sales and focus on net profit for a better return on investment and performance inclination. These are just a few major benefits businesses can gain through use of computer networking; it’s no wonder they spend millions of dollars for technology every year. Take Microsoft Sharepoint for example, last year alone, they spent over millions of dollars on innovations but made over hundreds of millions of dollars back on their returns of investments and profits. Sharepoint, a web-development platform has really proved indispensible to any business owner or business in need of a quick, professional, and functional website. About 5 years ago and the years preceding, you had to fully understand computer language, such as HTML, CSS, JavaScripts, and PHP to create a website Now, you just do it with the dragging and click of a button. Most likely, not as easy as 1, 2, 3, but it’s almost as easy as coloring a book. Although this may prove negatively on current professional designers, it has proved indispensible to businesses around the world, and that’s what new innovations ought to do; make life easier. It has also made the job a lot easier and reduced the cost of spending for website designers to most companies. One can reckon the force of how powerful technology can be, but at the same time how dangerous it could be to society.
In health and pharmaceuticals research, some corrupted scientist could invent a dose of drug that could be harmful or detrimental to society, or in the worst case scenario, wipe out the human population. Computer scientist must always be aware that an innovation of theirs could possibly be the vice versa outcome they had expected. This is where the movies and films such as iRobot and Frankenstein came about. Like all professions, good morals and values is essential to every step in research and development, let alone, life itself.
The ebb and flow of information isn’t just the presence and absence of information. It’s art and science combined, whether complex or compound, its value is crucial and vital on businesses all around the globe. For some it could mean a lot of money, but for the ones that truly have a passion in it, nothing is impossible. It’s the boundary between science and art, like the law of time, gravity, and the universe according to Albert Einstein. Time can only tell, but when solved, cracked, or broken; possibilities and new innovations are endless. For the time being though, they are just floating around, patiently waiting to yet to be discovered by a passionate artist/scientist.

April 30, 2010

Exam Essential: Internetworking

Know the possible causes of LAN traffic congestion
Too many hosts in a broadcast domain/storms, multicasting, and low bandwidth are all possible suspects of LAN traffic congestion.

Be able to distinguish the difference between a collision domain and a broadcast domain
Collision domain is an Ethernet term used to describe a network collection of devices in which one particular device sends a packet on a network segment, forcing every other device on that same segment to pay attention to it. On a broadcast domain, a set of all devices on a network segment hear all broadcasts sent on that segment.

Be able to distinguish the difference between a hub, a bridge, a switch, and a router
Hubs create one collision domain and one broadcast domain. Bridges break up collision domains but create one super duper large broadcast domain through use of hardware addresses to filter the network. Switches are really just multiple port bridges with more intelligence. They break up collision domains but create one large broadcast domain by default and also uses hardware addresses to filter the network. Routers break up broadcast domains (as well as collision domains) and use logical addressing to filter the network.

Know the OSI layers
It’s mandatory that you know the OSI layers and the function each layer provides. There are seven layers in the OSI reference model. The upper layers consist of The Application, Presentation, and Session Layers, and are responsible for communicating from a user interface to an application. The bottom layers consist of The Transport, Network, Data Link, and Physical Layers. The transport layer provides for segmentation, sequencing, and virtual circuits. The network layer provides for framing and placing of data on the network medium. Last but not least, the physical layer is responsible for taking 1s and 0s and encoding them into a digital signal for transmission on the network segment.

Remember the types of Ethernet cabling and when to use them
There are three types of cables that can be created from an Ethernet cable:

  • Straight-through
    • to connect a PC’s or a router’s Ethernet interface to a hub or switch.
  • Crossover
    • to connect hub to hub, hub to switch, switch to switch, or PC to PC.
  • Rolled
    • for a console connection from a PC to a router or switch

Understand how to connect a console cable from a PC to a router and commence HyperTerminal
You should know how to do this for the exam: Take a rolled cable and connect it from the COM port of the host to the console port of a router. Start HyperTerminal and set the BPS to 9600 and flow control to none.

Memorize the three layers in the Cisco three-layer model

  • Core
  • Distribution
  • Access