28 August 2010

The Ancient and Noble Art of Troubleshooting

Troubleshooting, it’s something we all do. It may be your parents Internet connection, the company photocopier, your kid’s car or the core network of a medium sized bank. However, troubleshooting is not like that, it’s more like football, years of watching and playing does not guarantee to make you a superstar. However, with troubleshooting, just like football, it does teach you enough so you have an opinion on how it should be done.

Capturing VLAN Tagged Packets and Microsoft Windows

Turns out the Windows Network driver implementation are so loose and uncontrolled that there is no consistent behaviour when capturing packets with VLAN tags.

Maximum Number of Insertions for GBICs

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Ever thought about whether a GBIC has a maximum number of insertions into a transceiver ? Surprising answer follows…..

Sharing Ideas – GLBP and HSRP

John McManus kicks off writing at EtherealMind with a look HSRP and GLBP First Hop Redundancy Protocols.

Best Technique for Date Formatting and the Global Problem – ISO8601

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When working in a global company, a major problem is the way that some countries use the wrong date formatting. Say hello to ISO8601, standard for date formats.

Average IP Packet Size | Slaptijack

“Yesterday, I calculated the average packet size for one of the networks I work on using data from 263986M “

Review: robtex.com – DNS and Peering Tool

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An astonishing resource that provide a lot details on BGP AS, IP addressing, ownership, whois, DNS checking and much more.

Reloading IOS Config at CLI for Dynamips/Dynagen

David Sudjiman show us how to save and reload Cisco IOS configurations from the command line in Dynamips / Dynagen.

Dynamips, Dynagen, GNS3 0.7, IOS15.0 and Snow Leopard OSX

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It works.

Using Choosy for OSX. A Better Way to Use Multiple Browsers.

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I use multiple web browsers all day. One for typical web, and another for network management. I need a way to easily select which one I want.

Notes on Cisco Catalyst 6500 Architecture. (Or What Does 720 in Supervisor 720 Mean ?)

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What does the ’720′ in the Supervisor 720 stand for ? Or, what do you need to know about Cisco C6500 switch architecture.

Key Change for Cisco IOS 15 – Feature Licensing and How We Work.

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Welcome to IOS 15, Feature licensing and complicated maintenance procedures….

Cisco Announces EOS and EOL Cisco IOS Software Release 12.4

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Cisco announces the End of Life and End of Support dates for 12.4. Before IOS 15.0 is even warming up, the previous version of 12.4 is already on life support.

Can You Learn Anything From Google or Facebook Data Centers ?

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Google and Facebook have been puffing themselves up about how clever they are at solving technical problems. Is it just cheap marketing, and is there actually anything that Enterprise computing can learn from what they have shared ?

Google DNS – Not Proving to Be ‘All That’

So I have been testing Google DNS server with the new tool that they just released. It might be early days, but it ain’t as fast as the alternatives for me.

Configuring Network Locations in Mac OSX.

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When you are working in a lab environment, you often need to connect your laptop to different networks so that you can test stuff. For simple change like an IP address or a default gateway a script is useful. But you may want to have a much more sophisticated profile, such as different proxy servers and multiple ethernet ports. And if you are working on different sites, each one with different IP addressing and DNS details, and maybe even different proxy settings or 802.1x. Mac OSX has a way for configuring multiple profiles for your Ethernet connection ( or Airport wireless).

Install GNS3 on Mac OSX Leopard

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This post looks at installing GNS3 on Snow Leopard and has a number of screenshots and some tips on making it go well.

Putty, the Command Line and NO Clicky Clicky

While it may be a personal preference for me, I believe that you should only use the mouse when you don’t know what are doing. If you have a repetitive task, then clicking the same thing over and over shows that you are poor engineer. Lets hack putty to work from the command line.