In Data Centers today there is one constant; perpetual change. That one element is what drives the limits of business and the foundational technologies that enable it. In a bold effort to keep pace with this concept of change, a very flexible and efficient Data Center is needed. A Data Center that can support scalable Layer 2 networks needed for high performance computing (HPC), resource pooling, workload flexibility and virtualization.

The truth is that today our Layer 2 domains are severely hampered by fundamental issues associated with their most basic governing element; spanning tree protocol (STP). In an effort to block links thus avoiding the creation of bridging loops STP is in effect limiting our scalability by creating bandwidth restriction. More often than not even the mechanism used by STP to converge can cause application disruption as STP maneuvers around failed links. This means that the typical approach to address this issue in most networks is to deploy smaller layer 2 domains with Layer 3 boundaries, thus affording STP more stability and scalability. This approach of scaling down the layer 2 domain however will not work in the Data Center because virtualization and HPC applications require larger Layer 2 domains in order to maintain server capacity and high availability in the same VLAN. This quandary was addressed with the creation of Cisco FabricPath.
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During Session 2 of our CCIE Data Center Written bootcamp, we talked about Virtual Device Contexts (VDCs) on the Nexus 7000 series in great detail. We examined the configuration, maintenance, and deletion of these powerful constructs.

One of the topics that I indicated I would save for the blog was the controlling of resource limits on the VDCs. We saw how easy it was to verify the default resource limits, but I indicated that I would elaborate here. Let us do it now!

Controlling the resources these VDCs can consume is done with Resource Templates. These templates set the minimum and maximum for shared physical device resources during the creation of the VDC. Here are the resources that are controlled with these templates and the default maximums for the default VDC resource template:

• IPv4 Multicast Route Memory – 8 MB
• IPv6 Multicast Route Memory – 2 MB
• IPv4 Unicast Route Memory – 8 MB
• IPv6 Unicast Route Memory – 4 MB
• Port Channels – 768
• SPAN Sessions – 2
• VLANs – 4096
• VRFs – 8192

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In this three part series here at blog.ipexpert.com, we are going to examine one of the key buzz terms in the modern Data Center – I/O Consolidation. Here is a breakdown of the articles and the order in which they will appear:

• Part 1 – An Overview of I/O Consolidation
• Part 2 – The Technologies
• Part 3 – Fibre Channel over Ethernet (FCoE)

In this first part, let us examine the overall I/O consolidation concept and ensure we have a strong foundation for the more complex articles that follow.

In an earlier series here, we examined Fibre Channel in great detail. You recall that this is a dominant internetwork technology for connecting the physical SAN. We also know that Ethernet is a dominant connection technology in the LAN portions of the Data Center. 
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Day 13 CCIE Security Written 3.0 Cleared!

Study Topics

• The Written Exam

Notes

• This exam reminded me so much of the CCIE R&S written. Just like that test, there is absolutely plenty of time to finish it. And just like that test, there is this strange mix of really, really easy questions, and then a handful of ridiculous questions that I just cannot believe someone could answer.
• Watch out for some questions that look impossible, however. If you really look and think about them, there is sometimes a pretty easy way to reason through the correct answer.
• There are multiple choice questions only on this exam. I did not even see any drag and drop!
• If you are an R&S person, you have a HUGE advantage with this exam. There was a bunch of questions that were super simple that were straight out of the R&S discipline.
• There is no BACK button. Be sure, super sure, before you click NEXT.
• By the way – just like the R&S – you have 100 questions to deal with.
• The coverage for the blueprint was very, very accurate. In fact, it seems like they went right down the list. Obviously the biggest bias is ASAs, IPSs, and IOS and Catalyst security features. But please, study every damn item on the blueprint. They are all there.
• Thank you to all of the people that have been following my challenge. I am quickly realizing the incredible impact that you are all making. I cannot lose. I can only win. And if winning isn’t everything, why do we keep score? :-)

Sources

IPexpert CCIE Security Written VOD

Comments

I cannot believe that I am going to schedule another CCIE Lab Exam tonight. Wow. Goosebumps.

Anthony Sequeira CCIE, CCSI
Twitter: @compsolv
Facebook: http://www.facebook.com/compsolv

Please hold a good thought for all of the IPexpert students that are in their final exam week. Congrats to those students that have already moved on and passed their written exam in advance of this testing week!

Here is what some students had to say about the recent run of classes:

“Anthony – just wanted to advise you I passed my written with a score of 937. The foundation was excellent in your training sessions. I’m looking forward to the troubleshooting.”
M. Tran

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