Category: Fabric
Is Controller-Based Networking More Reliable than Traditional Networking?
Listening to some SDN pundits one gets an impression that SDN brings peace to Earth, solves all networking problems and makes networking engineers obsolete.
Cynical jokes aside, and ignoring inevitable bugs, is controller-based networking really more reliable than what we do today?
Lock-In Is Inevitable – Get Used to It!
For whatever reason (subliminal messages from vendor marketing departments?), I’m constantly brooding about the vendor lock-in, its inevitability, and the way supposedly disruptive companies try to use the fear of lock-in to persuade naive customers to buy their products.
vLAG Caveats in Brocade VCS Fabric
Brocade VCS fabric has one of the most flexible multichassis link aggregation group (LAG) implementation – you can terminate member links of an individual LAG on any four switches in the VCS fabric. Using that flexibility is not always a good idea.
2015-01-23: Added a few caveats on load distribution
Improving ECMP Load Balancing with Flowlets
Every time I write about unequal traffic distribution across a link aggregation group (LAG, aka Etherchannel or Port Channel) or ECMP fabric, someone asks a simple question “is there no way to reshuffle the traffic to make it more balanced?”
TL&DR summary: there are ways to do it, and some vendors already implemented them.
Load Balancing Elephant Storage Flows
Olivier Hault sent me an interesting challenge:
I cannot find any simple network-layer solution that would allow me to use total available bandwidth between a Hypervisor with multiple uplinks and a Network Attached Storage (NAS) box.
TL&DR summary: you cannot find it because there’s none.
Facebook Next-Generation Fabric
Facebook published their next-generation data center architecture a few weeks ago, resulting in the expected “revolutionary approach to data center fabrics” echoes from the industry press and blogosphere.
In reality, they did a great engineering job using an interesting twist on pretty traditional multi-stage leaf-and-spine (or folded Clos) architecture.
Just Published: Juniper Data Center Switches
Want to know what the difference between Virtual Chassis and Virtual Chassis Fabric is? How Local Link Bias works? How ISSU on QFX 5100 works even though the box doesn’t have two supervisor boards? You’ll find answers to all these questions in new videos describing Juniper data center switches.
Just Published: Brocade VCS Fabric Videos
The Data Center Fabric Architectures update session in late June included a whole new section on Brocade’s VCS fabric and new features they added in Network OS 4.0. The edited videos have been published and cover these topics:
Infrastructure as Code Actually Makes Sense
When I heard people talking about “networking infrastructure as code” I dismissed that as yet another Software-Defined-Everything one-controller-to-rule-it-all hype. Boy was I wrong.
Unnumbered OSPF Interfaces in Quagga (and Cumulus)
Carlos Mendioroz sent me an interesting question about unnumbered interfaces in Cumulus Linux and some of the claims they make in their documentation.
TL&DR: Finally someone got it! Kudos for realizing how to use an ancient trick to make data center fabrics easier to deploy (and, BTW, the claims are exaggerated).