Show 16 – Big Hot and Heavy Switches – Part 1

A detailed look at the Big, Hot and Heavy Ethernet Switches with a large crew to talk about their practical experiences on design, selection and performance of Cisco Nexus switches. The result ? We don’t think the Nexus switches are very exciting, HP Flex10 modules are a problem, and so much more.

Due to people commitments we recorded a double length show which will be released in two parts. This is Part 1 and Part 2 will be released next weekend.

VSS & vPC – the real experience

We started with a look at the differences between Cisco’s Virtual Switching System (VSS) and their Virtual Port Channel (vPC) implementation of Multi-Chassis Etherchannel and what our preferences are for choosing and implementing. We like vPC both from a design and implementation perspectives but our experiences of VSS have been very poor and we don’t choose to use it in the Data Centre. In practical way we don’t like the way that VSS is conceptually the same as a stackable switch.

We also don’t have much time on the Catalyst 4500 because they aren’t used in our designs. Also, there are too many modules and Supervisors, and the technology is confusing. The lack of architecture information is poor.

Cisco Fabric Extender switches

We had a short look at the QoS implementation on the Cat6500, and expressed our dissatisfaction with the configuration and consistency of the implementation and some surprising tips on how to solve the QoS problem.

Service Modules

We discuss the use of Service Modules in the C6500 chassis and our experiences.

The Guests

You can find Jeremy Filliben at and @jfilliben.

You can find Steve Rossen on @steve

You can find Ivan Pepelnjak at and on @ioshints.

IOS Hints Live – San Jose September 2010

You can book to join the event at There are only a limited number of seats at this unique event where Ivan Pepelnjak and Greg Ferro will both be available to discuss, review and develop your designs.


Follow the Packet Pushers on Twitter (@packetpushersGreg @etherealmindDan@rovingengineerEthan @ecbanks) and send your queries and comments about the show to [email protected].  We want to hear from you!

Greg Ferro
Greg Ferro is a Network Engineer/Architect, mostly focussed on Data Centre, Security Infrastructure, and recently Virtualization. He has over 20 years in IT, in wide range of employers working as a freelance consultant including Finance, Service Providers and Online Companies. He is CCIE#6920 and has a few ideas about the world, but not enough to really count. He is a host on the Packet Pushers Podcast, blogger at and on Twitter @etherealmind and Google Plus.
Greg Ferro
Greg Ferro
Greg Ferro
Greg Ferro

Latest posts by Greg Ferro (see all)

  • Aaron

    The reason you put 3750s in a data center is to keep them from getting over 80F and dying a horrible death. We've replaced dozens of these guys in closets that are warm but still well within what tolerances should be.

    • Ethan Banks

      Were these 3750Gs? Curious what models were burning up on you. For all the headaches I've had with 3750s, overheating hasn't been one, but then again – almost exclusively deployed in DC environments as you point out handles the heat issue.