Due to my own laziness, I let my CCNP expire over a year ago, which means I have to start at the bottom. I finally passed the CCNA today.
CCNP Recertification
Study notes for the Cisco CCNP exam
Some T1 troubleshooting links
Posted in March 27th, 2006
by sean in
Turns out we had a bad CSU/DSU on a T1 link recently, the thing that made it more difficult was that it was internal to the router (WIC-1DSU-T1)
Troubleshooting serial links is done by testing different parts of the links by looping endpoints.
The basic procedure:
http://www.cisco.com/en/US/tech/tk713/tk628/technologies_tech_note09186a00800a754b.shtml
The difference between loopback dte, loopback remote, and loopback line with pictures. [...]
Cisco Support
Posted in March 10th, 2006
I’m a self professed Cisco bigot. I use the term “bigot” because that’s what the Nortel sales guy called me and the name stuck. I’ve also heard the term “customer evangelist” thrown around by marketing people — a customer who is happy with the company, and tells others about it.
Why do I willingly [...]
I’m a case-opening machine
Posted in March 9th, 2006
by sean in
It’s rare that I open a case with TAC, I’m usually able to figure things out with the help of the docs or by working at it. But this past week, I’ve been involved with several cases:
Upgrade problems - After swapping the flash in a 3660, we couldn’t store an image on the new [...]
Providing career guidance
Posted in February 23rd, 2006
I got a call from someone in the company yesterday whose husband is getting retrained and is considering a career in netword administration. They asked if I could meet with him to tell him about the career. I’m happy to, but what do I say?
Netword admin is such an inaccurate term. In both the places [...]
Post from blackberry
Posted in January 26th, 2006
by sean in
Just testing posts from the blackberry. I seem to get good ideas on the way to and from work, maybe posting them immediately will help!
A Case Study in Port Flooding
Posted in January 16th, 2006
An interesting thing happened last week that illustrates how understanding the behaviour of a packet travelling through a network explains the cause of some rather odd traffic patterns.
It was noticed that all active ports on a certain switch would simultaneously see traffic spikes in excess of 8Mbit/s, even though these ports were normally dormant. [...]
Online labs at Cisco
Posted in September 2nd, 2005
Just finished an online lab through Cisco’s Learning Connection called “Advanced BGP Design with BGP Community Attribute - Challenge Lab - LabOps - IP - Accelerate (SE)”
The CLC has a lot of labs, I look forward to doing more
Start here: http://forums.cisco.com/eforum/servlet/PrepCenter?page=BigSnippet.PrepCenter.PrepCenter_freeTrial_learning_connection
In this lab the object was to learn communities and route-maps. Basically you are [...]
Lowest, highest?
Posted in July 20th, 2005
by sean in
Networking is all about understanding the behaviour of the underlying protocols. Many of these protocols are deterministic, meaning they will always produce a predictable result for a given set of inputs.
This is achieved by using predictable values, such as MAC and IP addresses, and reproducable values such as cost and hop count. These [...]
GoDaddy Virtual Private Servers
Posted in July 3rd, 2005
CCNPRecertification.com, and some other sites, have run off my cable modem since inception. The server started to become bogged down after time, so I thought it time to pay for some off site hosting.
Dedicated servers were in the $100US/month range, and the $5/mo cheapie hosting deals didn’t have the features I needed. Virtual [...]
