RedWarriorNet

You may remember I posted a while back about an apparent bug I found in the IOS version 12.2(50)SG we were running on our 2 4900M switches in our datacenter.  We had issues with twingig modules not being detected, SFP’s being flagged as invalid serial numbers, and general havoc uplinking any switch.  Downgrading our IOS version to 12.2(40) was our only fix.  (Luckily the engineer who designed our datacenter did a great job building in redundancy, so it was easy to reboot them each at different times with no disruption to traffic!)  Well, the TAC engineer with Cisco took this issue back to the lab and here is what I heard from him this week:

“Sorry for the long delay on getting this going, but I have tested
12.2(50)SG in the lab and I did see the problems that you experienced.
Then I tested 12.2(52)SG and had none of these same issues.  So it looks
like to get past these issues you will need to upgrade to 12.2(52)SG.

Regards,

Matt Blanshard
TAC Engineer - LAN Switching”

First off, I think it is awesome that Matt would go back and test this to find the issue as well as to verify that it has been fixed in the newest code…I can’t imagine Microsoft going that far for a single customer.  Second, it’s great to know that we won’t have to deal with this issue when it comes time to upgrade IOS versions.  (I’m thinking we will probably wait until 12.2(52)SG gets a little maturity on it before switching to it.)  So, there’s the answer.  Apparently the issue we found was just a fluke with 12.2(50)SG.  So now we know.

A very good friend of mine gave me just the kick in the pants I needed today and at just the right time.  Prompted by his suggestion, I am officially commiting myself to studying for the CCIE R&S this year and next as part of my path to networking nirvana.  My reasons for backing off from continuing along the wireless path mainly stem from the offer of a great study partner for the R&S and the relative newness of the Cisco wireless track, which has me thinking that doing the CCIE R&S will be a great next step before going back to wireless.  I’m not sure how well this will be received at work, though, where getting one’s CCIE has generally meant then leaving and where they are needing me to learn wireless at breakneck speed.  I am hoping that doing wireless by day and Routing and Switching by night will bring me some balance and move me closer to both goals.

Why was this such good timing?  Because I couldn’t run this morning.  How are the two related you ask?  Well, in the past month I have taken up running and usually run between 1 and 2 miles each morning before the chaos of life takes over.  One of the things I like about running is that it is difficult to carry on a conversation with yourself in your brain while your lungs are screaming for air.  This gives me a break from thought and some time to just be.  This morning, though, due to my shin splints acting up a bit and my stomach behaving questionably, I opted to walk instead.  Of coure, my mind took this as an open forum to mull over everything it might find and I began thinking how certification study is much like preparing for a major race.  I’ve been reading quite a bit about how runners prepare for long distance races as I consider running a 15k next year and the thought processes behind their training and my own studies were striking.  The part that stuck with me the most was a runner explaining that it is important to view the training for the marathon you run as just, if not more, important than the actual race.  He basically said that the best runners are those that enjoy the process of training, not those who only run to see the finish line.  If you’re really serious about a career in IT, certifications are just like that.  There will always be another one to earn or renew and its important to pace yourself and plan for the long term.

For networking professionals, at least those who work closely with Cisco gear, the CCIE is arguably the longest distance race we run.  It involves many of the same emotional challenges of any long race, including the self-doubt, frustration, loneliness, and pain that can come as you run day after day preparing for a finish line months in the future that you have no clue if you will be able to cross.  It requires dedication and a self-discipline similar to that of an athelete training.  It requires support of family and friends cheering you on and even comforting you if you fall short.  It is definitely an accomplishment just to have attempted, but a thrill to win.

Right now, I feel equal parts fear and excitement.  I definitely feel like I’m the slowest, least prepared runner on the training team and that the other runners around me are wondering what I’m doing there, but win or lose I intend to give it all I’ve got, using BSCI as my starting point for my studies.  I feel like I’ll have to sprint hundreds of miles to catch up, but I’m willing to keep trying.  I’ll see you all along the road.

I just found out through working with a TAC Engineer on an issue where our brand spanking new Catalyst 4900M won’t accept the command to place a Policy Based Route map on a vlan interface that PBR will not be supported until an upcoming IOS release, most likely in June.   Ugh.  This is not the first weirdness we’ve had with our 4900M’s.  The first was with one of the 4900M’s we have deployed in our new datacenter core.  This switch displayed some weird behavior when we were troubleshooting what appeared to be an issue with a fiber uplink in a twingig module we had plugged into one of the ten-gigabit ports.  We shuffled around some known-good GBICs in these twingigs and next thing we knew, the ports had error-disabled due a Cisco “feature” that keeps you from using illegal hardware, giving us an error of “Unapproved GBIC” in the output of a show interface status.  A reboot got us our ports back, but to this day one of the ports still shows that error even though it works and TAC hasn’t been able to help us be rid of it.  Apparently, on most of the higher-end switches, the database that keeps track of GBIC serial numbers times out entries after a certain period so that you can reuse a GBIC from one module in the switch to another without much trouble…in the 4900M’s they have yet to perfect this.

Cisco TwinGig Module

Don’t get me wrong, the 4900M’s are definitely good hardware and allow you to double your port density in modules you don’t want to use TenGigabit in by using the twingig modules that give you 2 1Gig ports instead, while still giving you the option down the road of using half as many tengigabit ports.  That can be a very handy feature when combined with the port density they already have and is the reason we have 4 of them in the core of our datacenter.  I just wish Cisco had worked out a few more kinks before releasing them.

But enough complaining…it’s good to have job security in these uncertain times!  My BCMSN studies are coming along well and I’m up to chapter 8 in the self-study guide.  That doesn’t sound like much, but the self-study guide’s chapters are all pretty meaty.  I also managed to watch 4 hours straight of CBT Nuggets this weekend before needing a nap.  My lab setup is almost finished and I hope to get it accessible from my desk as soon as there is a lull in the datacenter cabling.  Until then, I hope to keep pushing on my reading.  I’ve already really enjoyed some of the information on MST, which allows you to combine multiple instances of spanning tree into one instance, saving resources and allowing you to more easily use redundant links for load-balancing instead of just leaving them in blocking.  I’ve also really enjoyed the section on etherchannel, particularly doing more sophisticated load-balancing over multiple etherchannel links.

I’ve neglected my humble little blog lately and I’m sorry I have.   Since I have been gone, I have successfully passed my ONT exam, making me 1/4 of the way to my CCNP.   :)  I really have to say that this exam is much more focused on theory than practice than many of the Cisco exams I’ve taken and a lot of the material just isn’t possible to recreate in a home lab.  Here’s what I used to study and pass:

CBT Nuggets - These are entertaining and great for getting a basic grasp of exam concepts.  I felt that they really helped with making information “stick.”

Trainsignal Videos - These are a little drier than the CBT Nuggets, but have much more detail to them along with some information that may not be covered by the exam, but is good to know for real life.  I credit these with being the most helpful towards passing my exam of all my study resources, but I’d recommend you use them after you have used the other resources you plan on studying as they can be overwhelming to just dive into.

Cisco Press Exam Guide - This book alone wouldn’t have given me a passing score and didn’t on my first exam attempt, but I think they are still necessary to read and should definitely be a part of anyone’s library studying for a CCNP exam.

The Cisco website, on the job hands-on with QoS, and some work wih the NetworkSims simulator and a 1710 router.  Like I said, it’s not really feasible to recreate some of the objectives in a home lab, but I found that the simulator I used was pretty good for the price and helped me practice.   My 1710 gave me some good hands-on time with both the MQC and the SDM interfaces.

Now I’m studying for the ISCW and plan to have a study guide posted for that as well as soon as I’ve gotten deeper into my reading.   My strategy for this one is as follows…

1.  Watch the CBT nuggets for an exam objective, for example, watch all the nuggets for MPLS.
2.  Read the Cisco Exam Guide chapters relating to that objective, so here that would be all the chapters relating to MPLS.
3.  Once I’ve made it through the Exam Guide and Nuggets, watch each objective in the Train Signal series one at a time.
4.  After watching each Train Signal video, get some hands-on lab practice as well.
5.  Take a practice exam and repeat until scoring in the 90%’s for every objective!

In somewhat related news, I start a new job in 2 weeks as a full-blown Network Engineer!!!!   Woo-HOO!  I’m very excited to be officially doing what I was unofficially doing and have a permanent home rather than remaining a contractor.