Posts by blake
A Little OSPF Story
Here is an exert from Aaron’s OSPF Story: Right in the middle of the config, I see “area 50 nssa”. Yes, this single non-backbone area with no real costs being advertised was configured as a not-so-stubby area. Not only did they go out of their way to make it a non-backbone area but they also wanted it [...]
10 Things You Must Know About Link-State Routing Protocols
Routing protocols are able to dynamically update and talk to each other about changes that may occur in a network, such as a link going down. The beauty of this is that, if designed properly, redundant links can quickly be found with out the network going down or users even knowing there is an issue. [...]
Core EIGRP Topics
EIGRP is an important topic on the CCNA exam. Just as important as RIP is for the CCENT exam. Currently I’m studying for my CCNP ROUTE exam and reading about the EIGRP routing protocol. While there are some new topics about it that I didn’t learn when preparing for my CCNA exam, everything that I’m [...]
CCENT Study Guide Book Review
I wake up at 4:30 am every morning to get a head start on the day and to my surprise on Thursday 10/20/2011 Junstyn Windsor left a very nice post on the Networking Exam Academy Facebook page just a couple of hours before I had woken up. It was very nice of him to do [...]
Why NOW is the time to get Certified
Although it is rough out there in terms of jobs, if there is one industry that is constantly thriving, changing, and evolving; it’s technology. And not just technology is general, but specifically computers and networking. According to the Bureau of Labor Statistics, all computer-related sales are expected to grow faster than any other job through [...]
Online Network Simulator (beta) 0.0.2 Released!
I released a new minor update to the Online Network Simulator (beta) this morning. Version 0.0.2 fixes a few bugs from version 0.0.1 and I added support for the ‘show version’ or ‘sh ver’ command. Obviously there is still a lot of work to do, but there currently is a lot of functionality to help [...]
Increasing redundancy and service performance
Stuff like this fascinates me… 37Signals talks about how they came about getting a 1.5 gigabit internet connection.
RIPv2 Explained
The Need For Routing Protocols
Routers within a network use routing protocols to talk with one another so that updates and changes to the network can be adapted to dynamically without any major involvement from the network administrator. A router in a network has a routing table so that it can keep track of where his fellow routers are. It is like his contact list or address book. If routing protocols didn’t exist we would have to configure static routes manually to each router in the network on every single router. This can be a lot of work if you have a lot of routers. If you only have static routes and one of your links goes down in the middle of your network there is no real way for the routers to update each other on the status of the broken link. YOU, the network administrator, will have to go into every single router on the network and remove the bad link and define an alternate route. Again, this can be a lot of work if you have a lot of routers in your network creating a lot of down time.
Using a routing protocol will solve this issue of having to do all this manual work every time there is a change in your network. In the rest of this article we are going to focus on RIPv1 and its predicesor RIPv2, but there are several other routing protocols that we will learn about later for the ICND2 Exam and the CCNA Exam. RIP is a great tool to learn about routing protocols because it is simple to understand and easy to configure. Other routing protocols like EIGRP, OSPF and IS-IS are more advanced than RIP, but build upon RIP’s core functionality. We focus on learning RIP first because it builds a solid foundation of Routing Protocol knowledge that will make learning more advanced routing protocols much easier. For the ICND1 Exam you will need to know everything about RIPv2 (and RIPv1), and have only basic understanding for EIGRP, OSPF, and IS-IS.
So, what is a routing protocol? Basically it is a language or format that routers use to communicate with each other, so that they can automatically learn about new routes and make new routing dicisions incase a link goes down somewhere in the network. Having this ability to automatically make decisions can help keep your network running smoothly even when problems arise (Smoothly will depend largely on if you have redundant links in your network or not).
How to connect your iMac to your cisco router
I used to have a very old pentium II laptop that I saved because it was my only computer that had a serial port that I could use to connect to my Cisco router via a console cable. Well, a few months ago I got rid of my old laptop and now I only have [...]
Network Simulator Update – See a list of available commands
In this video update today about my online network simulator progress I just wanted to show you the ‘?’ command that will allow you to see a list of available commands.