Category: Data Center

During the final part of the IPv6-only data centers webinar Tore Anderson described his deployment guidelines and answered a few more questions.

Another day, another stateful debate, this time centered on the number of flows per hypervisor. Previously I guestimated 2.500 connections-per-second-per-(user-facing)gigabit and 37.500 concurrent sessions per user-facing gigabit, but wanted to align my numbers with reality before reaching any conclusions.

My web sites are way too small, so I asked a few of my friends to help me get more realistic figures.

A while ago I wrote about ATAoE and why I think a layer-2-only TFTP-like protocol shouldn’t be used these days. As always, the answer to that black-and-white opinion (and I’m full of them) is “it depends” – ATAoE works great if you do it right.

The edited videos from VMware NSX Architecture webinar are published on my demo content web site and on YouTube. Enjoy!

One of the holy grails of data center SDN evangelists is controller-driven traffic engineering (throwing more leaf-and-spine bandwidth at the problem might be cheaper, but definitely not sexier). Obviously they don’t call it traffic engineering as they don’t want to scare their audience with MPLS TE nightmares, but the idea is the same.

Interestingly, you don’t need new technologies to get as close to that holy grail as you wish; Petr Lapukhov got there with a 20 year old technology – BGP.

My keynote speech @ PLNOG11 conference was focused on (surprise, surprise) overlay virtual networks and described the usual motley crew: The Annoying Problem, The Hated VLAN, The Overlay Unicorn, The Control-Plane Wisdom and The Ever-Skeptic Use Case. You can view the presentation on my web site; PLNOG organizers promised video recording in mid-October.

Just in case you’re wondering why I keep coming back to PLNOG: they’re not only as good as ever; they’re getting even more creative.

I must have confused a few readers with my blog posts describing Arista’s VARP and Enterasys’ Fabric Routing – I got plenty of questions along the lines of “how does it really work behind the scenes?” Let’s shed some light on those dirty details.

Not surprisingly, the unorthodox ideas of Tore Anderson generated plenty of questions, so he spent ~20 minutes answering them.

Plexxi has an interesting problem. They have a shiny new solution that requires unorthodox approaches to network forwarding and allows them to implement potentially cool concepts like affinities (traffic engineering in disguise). They also need to sell these new concepts to the customers, and the first question I would ask after recovering from a hefty dose of cool-aid is "and how do I configure these affinities?"

Remember Tore Anderson’s IPv6-only data center design he described in last June’s webinar? Wondered how he got it done? The secret sauce he used is SIIT – the stateless IPv6-to-IPv4 translation technology. His trick: turning it around.