Problem Diagnosis With Ping By Steve Waddington The two most used tools, and almost always the first used to diagnose a network problem are traceroute and ping. The results they return are however most often misunderstood or interpreted in a way that leads to an incorrect conclusion. Let’s take the …

It’s time to vent some frustration everybody!! If you have worked on Cisco devices for any length of time, or even if you have just started work with Cisco routers, you know that the Cisco command line interface can be a frustrating thing. The consistency of the syntax of a given …

Everyone remembers the original movie TRON where the character Flynn, played by Jeff Bridges, is sucked into the microscopic world of computer games.  In the movie the villain was the Master Control Program or MCP who would take programs OFFLINE if they misbehaved. Switches have their own MCP (of sorts) …

How to Configure SSH (Secure Shell) For Remote Login on a Cisco Router By Don R. Crawley Prior to the introduction of SSH in the Cisco IOS, the only remote login protocol was Telnet. Although quite functional, Telnet is a non-secure protocol in which the entire session, including authentication, is …

Network Routing Protocols – IGRP, EIGRP, OSPF, ISIS, BGP The purpose of routing protocols is to learn of available routes that exist on the enterprise network, build routing tables and make routing decisions. Some of the most common routing protocols include RIP, IGRP, EIGRP, OSPF, IS-IS and BGP. There are …

Entering the Nexus If you have a data center or if you have any services running in a data center then at some point you may have considered Cisco’s Nexus switching platform.  Rightly so, Cisco’s Nexus platform promises and delivers huge flexibility and scalability gains within the data center. FabricPath To provide this next …

As wireless Internet services grow and expand, it seems that the industry is on a constant upward spiral. The potential for increased connectivity seems to be virtually limitless, and the spirit of competition and desire for profits will almost certainly motivate wireless providers to continue to strive for new heights …

Per Wikipedia – A Mnemonic is “A device such as a pattern of letters, ideas, or associations that assists in remembering something” As network engineers, we are constantly tasked to remember details (and recall easily) about how networking technology works.   One of the easiest ways to commit some of …

Too often we get asked by our readers “What is the easiest/fastest/best/simplest way to pass the Cisco CCNA or CCNP exam”.  Too many people want a quick answer or a quick fix.  We live in a fast paced society where everything needs to be done quickly so we can get …

Cisco routers, as well as most other computer devices, have the ability to log messages about everything they do. These log messages are invaluable when trying to troubleshoot a really difficult network issue. The problem with Cisco routers is that when you enable logging, the default size of the log …