Sunday, September 10, 2017

High CPU on Nexus 3K - Solved

In this blogtorial, I will demonstrate how I used 'ethanalyzer' on a Cisco Nexus 3K to solve an intermittent issue -- random adjacency drops of various routing protocols. Before we get into the details. let me first share with you on how I got involved in this troubleshooting to begin with. My good friend and colleague "BGP" bill aka self proclaimed "Multicast Guru" 😊 turns around says "Hey Weezy, you are a CCIE right? I have an open case with Cisco for a month why don't you just solve this issue?". Hmmmm ... above all else, one thing I've learned from the journey of becoming a CCIE is that I know very little. There is so much more to learn than you can imagine. In any case, I thought it was a noble challenge and as a bonus it peaked my curiosity. So Bill and I started chatting about the issue and as we were going through the motions, he gave me a great piece of information that would eventually steer me down the path to solving the issue, "Pete reported that he saw HIGH CPU usage compared to other similar routers".

So my 2 questions were:

Tuesday, January 10, 2017

ITHITMAN GIT Repo - https://github.com/ithitman/

Well it is official. I've signed up for a git hub account. I can now start publishing some open source tools on my free time to help my fellow engineers and tech enthusiasts.

Here is the link to my git repo that you can clone for yourself and contribute or use it.

https://github.com/ithitman/

Sunday, January 1, 2017

Interaction between TLP (Tail Loss Probe) and SolarFlare EF_DYNAMIC_ACK_THRESH

In this blogtorial I will briefly discuss a performance issue that had me stumped for a bit. But after some googling around I stumbled up on the answer. I then started to take apart the RFC to gain a better understanding at the mischievous protocols at play. Oil powers the world and water sustains life, however they do not mix well together and the same concept applies here. Tail loss probe on its own is a great feature reducing the time it takes to detect packet loss and makes the TCP connection much more efficient. SolarFlare EF_DYNAMIC_ACK_THRESH is also a great feature which helps TCP performance. But enable these features at the same time and your TCP performance will suffer greatly.

Sunday, December 4, 2016

CCIE #52966 R&S - First Attemp Pass

Hello fellow future CCIE's and blog readers ... I've done it and I can't express my excitement in words. I know I have not posted in a while due to personal issues right after achieving my CCIE, however I am starting the blog engine again. In this blog I am going to document some important information regarding my preparation, stuff I did before/during/after the lab exam, and hopefully give some insights / motiviation that might help you during your exam.

Lots of people ask me how do I feel being a CCIE? First off, I feel no different as I am the same engineer I was before I passed the CCIE exam, but the journey of becoming a CCIE has greatly changed my attitude and my day to day behavior on how I approach issues (both personally and professionally). The journey itself was much more important to me than passing the actual lab exam ... and as you go through your preparation keep one thing in mind "Championships aren’t won in the theater of the arena. They are won in the thousands of hours of training ... when everyone else is sleeping. That’s where it’s won. The heart of a champion is a light switch that’s always on – it doesn’t go on and off when someone’s watching – it’s constant" - (Greg Plitt RIP). The passing of the exam was just a general indication of my progression so do not get discouraged if you fail the first time. Just keep trying till you get to the finish line and grab that number.

Wednesday, April 13, 2016

Date Set - 5/27/16 - CCIE R&S v5 1st Try

Booked my CCIE R&S v5 lab on 5/27/16 in San Jose, CA. Check back here for more updates on my experience ...


Let's do this ...

Wednesday, December 23, 2015

This is why I post ...

I normally post "How-to articles..." however, I figured this time I'd share a thought that came into my head yesterday as I was watching "Grey's Anatomy". Now I am not particularly a big fan of that show but my wife had a surgery recently and while she was on bed rest, I started to watch the show with her. In one of the episodes, it was revealed that Meredith's mother wrote down all of her research because she was going to get Alzheimer and would eventually forget everything. As I was watching this episode, suddenly a thought popped into my head ... "why do you write how-tos/blogs? ... it's time consuming ... you could be doing something else instead...?" ... As I laid awake mulling over on this thought ... I realized that there are more than one reason as to why I write ...