I recently saw posts from a few sources on a new initiative backed by a consortium that includes Google and OpenDNS to attempt to improve the overall speed of the internet by optimizing the way DNS works on the internet. If you think about it, a great deal of internet traffic is high-volume requests for things like photos, music, video, and the like. You may know, then, that content providers like Akamai have positioned themselves globally around the world to provide this content at a relatively close physical location to those requesting it.
This is the first in what I hope to be a useful series on configuration/walk through videos aimed at educating up-and-coming networking professionals on some of the more fundamental concepts. Today we’ll be looking at static routing and how to configure it in a small Cisco network. Below are the lab files (GNS3) and the videos themselves. Download the Lab Outline Download the GNS3 Lab used in this video Since it’s a new Youtube channel, I’m limited to 15 minutes per clip, and therefore had to break it into two parts.
I’m pleased to announce a new feature on the site. I’m going to start publishing some articles on more fundamental concepts in networking in the form of video walk throughs / labs. I wanted to free up the main blog feed for some more advanced topics, and a lot more of an overall network design discussion, as well as the occasional fun stuff. Several people have approached me in the past about making something like this that would help beginners learn the fundamentals, and at the time I wasn’t able to, but I feel like I’m able to do them now.
The television and video game industry are just absolutely RIDDLED with terrible attempts at referencing technology. Typically, these scenes will try to delve into some sort of computer-like concept, often related to computer networking, to try to improve the modernity of the content. Before you say anything, I did pull a bit of inspiration from this Cracked article, but there are a few I’ve encountered on my own. I hope you enjoy!
Over the past few years, I’ve made some observations about the people I’ve worked and communicated with. Some of these people were colleagues, others acquaintances, and still others were simply bloggers that I look up to. I’m talking specifically of those people that are in my field of Network Engineering, and they all share a few traits in common. I’ve deemed a few of these traits to be important things to remember when trying to make yourself a better network engineer, and a better IT professional in general.
A recent and relatively quiet IOS release allows the Catalyst 2960 platform to perform limited Layer 3 Switching (See this thread and this blog post). There are limitations - for instance, it cannot run any sort of routing protocol, so routing must be done statically. Up to 16 static routes can be entered, and routing is limited to SVI’s (maximum of 8), as the platform is not able to route to or from a physical interface, like you’re able to do with most layer 3 switches.
Link state routing protocols maintain topology tables to determine the best candidate to place in the routing table. EIGRP is no different - it uses this topology table to build a vision of the network from the perspective of each participating router. This topology table is reviewed by the routing algorithm (in the case of EIGRP, it is DUAL) and decisions are made regarding what gets placed into the routing table.
One of the most important skills to have when it comes to basic networking is the ability to look at a routing table and determine exactly where a packet will be routed when it comes to a router. Sometimes a routing table is relatively simple, and this process is easy. However, many times this is not the case. In large networks, especially networks that implement a hub and spoke design where core routers are often required to know hundreds of routes or more, this can be tedious.
At the end of my Senior Design sequence, a professor asked if I had time to look into IPv6 Mobility. At the time, I had to tell him no, since it was considered to be out of scope for the project. It’s a shame really - the concept of IP Mobility in general is extremely fascinating. I’d like to point out that IP Mobility is well-documented technology - and I’d rather not spend a lot of time explaining it, since I’m sure there are articles out there that do a much better job.
We’ve all heard about tools like Darik’s Boot and Nuke for performing secure hard drive wipes suitable for even the most paranoid. However, in a pinch, there’s an alternative that often goes overlooked, but is able to erase data at a level comparable to all the usual standards like DoD (or even the incredibly obnoxious 35-pass Guttmann method) The ‘shred’ utility exists on nearly every popular Linux live CD/DVD and can be executed in a live environment to do the job when it’s all you have.
Ah - I can finally breathe a sigh of relief, for I am finally done with my Senior Design sequence, as well as my undergraduate education. I’ve been feeling a little out of place, actually, since I’ve been in research mode for the last 9 months for my IPv6 project. So, after a short break, I decided to get back into things that I was just getting started with before all of that started.
Arguably the most important day for IPv6 since it was created is World IPv6 Day, which falls on June 8th, 2010. This has been a highly publicized day when the top internet content providers like Google, Facebook, and Yahoo provide native IPv6 DNS records to their sites. But what does this mean? And how can you be prepared? Most of all, what will break, if anything? What will happen on World IPv6 Day?
I’m pleased to announce the first post in my blog’s new location, here at keepingitclassless.net). I have been running a casual blog from my house for the past two years with mixed success. Residential internet connections as they are, this was usually hit or miss regarding whether or not my blog was even reachable. I’ve moved all that content to a web host which should prove to be much more reliable.
Subnetting, in short, can be thought of as an adjustable “slide rule” that tells the network infrastructure the logical size of a sub-network, or subnet. This is useful if you know how many IP addresses you’ll to suit the needs of a predetermined number of PCs, so you can plan the size of your subnets to match that requirement. With IPv4, subnet masks are used to determine how big the subnets are.
That’s right, I’m taking the 640-802 exam from Cisco to attain my CCNA (Cisco Certified Network Associate) certification in one week! The last four weeks have been quite eventful, although I’m ashamed I didn’t really start studying REALLY hard until about 3 weeks ago. Regardless, I’ve learned a lot! I’ve been following the book “31 Days Before Your CCNA Exam”, which is essentially a daily planner for study topics regarding CCNA material.
Often, especially in medium to large networks, it’s crucial to monitor the traffic traversing your networks. Those in the networking industry know that tools like tcpdump and wireshark are crucial for deeply investigating network issues. Even developers use these tools to diagnose issues with applications utilizing network resources. Many times, it is helpful to install/use one of these tools to figure out exactly what’s traversing the network, by seeing the frames and packets themselves, in a visual way.
Setting up a new Android Development Environment in Eclipse? Having troubles? Maybe one of these two solutions will help: PROBLEM #1 I recently re-imaged my PC and decided to build my Android Development Environment from scratch. Some recent modifications to my eclipse installation messed it up so I cut my losses and started over again. This time around, I noticed that Eclipse Helios was available for download, and not only that, it was the first version of Eclipse to offer a 64-bit version of the IDE for windows.
This will be a short one (cough, I’m at work, cough) but I gotta share these links. Downloadsquad.com shares some great links, but these stories in particular give lists of apps that any computer-savvy person must at least be aware of. Before you go googling to download some shoddy software that may or may not do what you want it to, check out these lists first: http://www.downloadsquad.com/2008/09/02/24-killer-portable-apps-for-your-usb-flash-drive/ http://www.downloadsquad.com/2008/10/01/24-great-open-source-apps-for-admins-and-technicians/ http://www.downloadsquad.com/2009/05/18/40-great-open-source-apps-and-games-to-trick-out-your-new-windows/ Again, thanks to Downloadsquad.
I’ve been seeing a lot out on the internet about proxy servers and how to use them to circumvent your school or workplace internet filters. Lifehacker recently posted an ~EIGHT PAGE~ walkthrough on how to set up such a proxy at home. This is entirely too complicated. Not only is it a long walkthrough, but your traffic is still unencrypted. Unless your school, work or other bought their filter technology more than 4 years or so ago, they can still see the header of your packets and where they’re headed.