In July I wrote about an Amazon Kindle version of my Data Center Design Case Studies book and complained about their royalties model. Someone quickly pointed out how to adapt to their system: split the book into multiple volumes and charge $9.99 for each.

It took me months to get there, but the first two volumes are finally on Amazon:

I was listening to the I2RS Packet Pushers podcast a while ago and was more than glad that when Greg Ferro yet again mentioned the complexity of OSPF, someone simply pointed out that controllers would not reduce the complexity; if anything they would increase it.

Bryan sent me an interesting question:

When you have the opportunity to use LAG or ECMP, what are some things you should consider?

He already gathered some ideas (thank you!), and I expanded his list and added a few comments.

Purpose: resiliency or more bandwidth? For resiliency you want fast failure detection and the ability to connect to multiple uplink devices, for more bandwidth, you want better hashing.

Last week’s Interop New York was hard work (three workshops in two days), but also lots of nerdy fun. I love doing workshops with smart participants who bring their real-life problems to the room and challenge my assumptions and conclusions, and I had plenty of these interactions during the week. Thank you all (you know who you are)!

The stars have finally aligned, and after months of scheduling Jason and myself found time to chat about network automation tools and all the other exciting things Jason is doing (and blogging about).

We started with easy topics:

Every now and then I get an email from a subscriber having video download problems. Most of the time the problem auto-magically disappears (and there’s no indication of packet loss or ridiculous latency in traceroute printout), but a few days ago Henry Moats managed to consistently reproduce the problem and sent me exactly what I needed: a pcap file.

TL&DR summary: you have to know a lot about application-level protocols, application servers and operating systems to troubleshoot networking problems.

After covering the basics of MPLS, my discussion with Seamus Gilchrist turned to the basics of MPLS Traffic Engineering.

The video of that discussion is available in the MPLS Essentials webinar.

During one of my ExpertExpress engagements I got an interesting question: “could we replace a pair of central firewalls with iptables on the Linux server?”

Short answer: Maybe (depending on your security policy), but I’d still love to see some baseline scrubbing before the traffic hits the server – after all, if someone pwns your server, he’ll quickly turn off iptables.

During the last round of polishing of my Designing Infrastructure for Private Clouds Interop New York session (also available in webinar format) I wondered whether one could use the recently-launched UCS Mini to build my sample private cloud.

I love reading blog posts on Plexxi blog (you SHOULD add them to your RSS reader) and the “It’s the Application, Stupid” series from Mat Matthews is no exception. What pleasantly surprised me was that a large enterprise came to the same conclusions I’m preaching for the last few years.