Category: Data Center

The original idea behind cloud-as-an-appliance design came from Brad Hedlund’s blog post in which he described how he’d build a greenfield Hadoop or private cloud cluster with servers connected to a Clos fabric. Throw virtual appliances into the mix and you get an extremely simple and versatile architecture:

In his recent blog post Joe Onisick wrote “What network virtualization doesn’t provide, in any form, is a change to the model we use to deploy networks and support applications. [...] All of the same broken or misused methodologies are carried forward. [...] Faithful replication of today’s networking challenges as virtual machines with encapsulation tunnels doesn’t move the bar for deploying applications.”

The recording of recent Enterasys Robust Data Center Solutions is available on ipSpace.net demo web site.

You can watch (or download) the following videos:

With the recent plethora of overlay networking startups and Cisco Live Dynamic Fabric Architecture announcements it’s time to revisit a blog post I wrote a bit more than a year ago, comparing virtual networks and voice technologies.

They say a picture is worth a thousand words – here are a few slides from my Interop 2013 Overlay Virtual Networking Explained presentation.

The last part of the ProgrammableFlow webinar described typical use cases including Cloud-as-an-Appliance, traffic steering (used by appliances like Radware DefenseFlow) and hypervisor switching with PF1000. Predictably, the use cases were followed by a lengthy Q&A session.

Nicolas Vermandé sent me a really interesting question: “I've been looking for answers to a simple question that even different people at Cisco don't seem to agree on: Is it a good idea to class IP traffic (iSCSI or NFS over TCP) in pause no-drop class? What is the impact of having both pauses and TCP sliding windows at the same time?”

During the recent Data Center Fabrics Update webinar Dan Backman from Plexxi explained how their innovative use of CWDM technology and controller-assisted forwarding simplifies deployment and growth of reasonably-sized data center fabrics.

I would highly recommend that you watch the video – the start is a bit short on details, but he does cover all the juicy aspects later on.

In the Optimal L3 Forwarding with VARP and Active/Active VRRP blog post I made a remark along the lines of “Things might get nasty [in Arista EOS Virtual ARP world] if you have configuration mismatches”, resulting in a lengthy and amazingly insightful email exchange with Lincoln Dale during which we ventured deeper and deeper down the Virtual ARP (VARP) rabbit hole. Here’s what I learned during out trip:

The true OpenFlow zealots would love you to believe that you can drop whatever you’ve been doing before and replace it with a clean-slate solution using dumbest (and cheapest) possible switches and OpenFlow controllers.

In real world, your shiny new network has to communicate with the outside world … or you could take the approach most controller vendors did, decide to pretend STP is irrelevant, and ask people to configure static LAGs because you’re also not supporting LACP.

I was reading What Network Virtualization Isn’t¹ from Jon Onisick the other day and started experiencing all sorts of unpleasant flashbacks caused by my overly long exposure to networking industry missteps and dead ends touted as the best possible solutions or architectures in the days of their glory: