I have to admit I was somewhat surprised by the lab test results I’ve published in my previous CB-WFQ post. It looks like we’ve been fed misleading information about (classic) CB-WFQ behavior for years.

Don’t tell me that things are completely different with HQF implemented in IOS releases 12.4(late)T and 15.0. I know that … but 95+% of the installed base do not use those releases.

Let’s see whether you can figure out what my next lab test results showed. I’ve been running three parallel TTCP sessions on ports 5001, 5002 and 5003 across a 256 kbit point-to-point link. Here’s the relevant part of my router configuration:

Decades ago when I was still in high school and working on a programming project during the summer break, an IT old-timer gave me the following bit of advice: “Remember, God created professions so that everyone could do the job he’s qualified to do”. It took me years before I understood what he had been trying to tell me, but this seems to be an industry-wide disease. Judging by some of the e-mails I receive a lot of people who are proficient in other IT specialties think they can configure the routers with a little help of good uncle Google and free support from fellow bloggers.

Reading various documents describing Class-Based Weighted-Fair-Queueing (CB-WFQ) one gets the impression that the following configuration …

class-map match-all High
 match access-group name High
!
policy-map WAN
 class High
  bandwidth percent 50
!
interface Serial0/1/0
 bandwidth 256
 service-policy output WAN
!
ip access-list extended High
 permit ip any host 10.0.3.1
 permit ip host 10.0.3.1 any

… allocates 128 kbps to the traffic to/from IP host 10.0.3.1 and distributes the remaining 128 kbps fairly between conversations in the default class.

I am overly familiar with weighted fair queuing (I was developing QoS training for Cisco when WFQ just left the drawing board) and was thus always wondering how they manage to implement that behavior with WFQ structures. A comment made by Petr Lapukhov re-triggered my curiosity and prompted me to do some actual lab tests.

The answer is simple: CB-WFQ does not work as advertised.

If you want to understand the real impact of the recent Data Center hype without getting pulled into the technology morass the vendors so copiously spread in their white papers, read the Foundation of Green IT book published by Prentice Hall. Its author, Marty Poniatowski, uses two case studies to illustrate enormous savings that can be realized through server and storage consolidation. I loved the first half of the book: the author avoids the technology issues (I loved the introduction to RAID: “I do not cover RAID background … the Internet has a wealth of information on RAID”) and uses real-life data gathered in actual project to illustrate the savings. Each case study has several chapters, ranging from starting point discovery through implementation plans and ROI analysis; exactly what you need if you’re considering going down the data center redesign path. The “Desktop Virtualization” and “Data Replication and Disk Technology Advancements” chapters are thrown in for good measure.

The author makes the server and storage consolidation case studies even more interesting by describing actual products/solutions and inserting screenshots of actual reports throughout the text. Not surprisingly, he’s describing what he knows best: HP servers, EMC storage and VMware virtualization; a clear indication how far Cisco has to go to win the hearts and minds of the data center market.

During the IPv6 summit in Slovenia I’ve participated in a roundtable organized by our Ministry of Higher Education, Science and Technology. One of my points was that the government should require true IPv6 support in all its IT procurement processes to promote IPv6 adoption (I have to admit I’ve borrowed a few ideas from Geoff Huston’s “Is the Transition to IPv6 a Market Failure?” article) … and one of the participants (coming from the Service Provider industry) answered that “that’s common hygiene”. I’m not so sure.

Topics like this are covered in my Enterprise IPv6 Deployment workshop. Learn more about my workshops from my web site.

I’d like to thank all the readers that took time and responded to my question about the failure of my Deploying Zone-Based Firewalls book. The sad short conclusion is: while everyone would love to have an electronic copy of the book, the technology and the mindsets are simply not ready yet. Here are the details:

Approximately a month ago Alcatel-Lucent launched Converged Backbone Transformation (are they sharing marketing wizards with Cisco … or is the excessive hype an industry-wide phenomenon?): a visionary(?) convergence of IP and optical technologies. If you haven’t heard about it yet, you could try to start with the IDC report published on Alcatel-Lucent’s web site (I’m always amazed how some people manage to tell so little in so many words).

Great news: Cisco launched a new series of midrange routers on Tuesday. They're very probably great products (I wouldn't expect less from Cisco). Also as expected, their marketing department couldn’t help itself (yet again) and had to position the launch as a universe-changing event: this time they Revealed the Borderless Network and spent loads of money producing “viral videos”. OK, maybe their average customer is stupid enough to fall for those tricks; I’m positive you’re not … so let’s see what’s really new (here's what Cisco admits is new after you've got past all the marketing fluff):

A quick question for you: in two years since my Deploying Zone-based Firewalls digital short cut (marketese for downloadable PDF) was published, we’ve sold around 200 copies of it. Obviously we’re doing something wrong and I’d appreciate your opinion: is it the topic (are you using ZB firewall on Cisco IOS?), the format (would you prefer paper copy?), the platform (Cisco IOS as a firewall), pricing ($14.99 for 112 pages) or something else?

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