Category: Fabric

While the large data centers increasingly use BGP as the routing protocol within their fabrics, the enterprise engineers tend to shy away from that idea because they think BGP is too complex/scary/hard-to-configure/obsolete/unknown/whatever.

It’s time to fix that.

Online webinars are great, but many engineers still prefer live workshops – they’re an excellent opportunity for unrestricted 2-way communication and exchange of ideas – so I decided to turn a few of my best webinars (or webinar tracks) into workshops, and Gabi Gerber, the wonderful organizer of Data Center days in Switzerland took over the logistics, resulting in the first-ever Data Center Fabrics workshop in Zurich in late March.

In theory, you should shut down a network device with a well-defined procedure:

• Drain the traffic from the device;
• Verify the device is no longer forwarding traffic;
• Turn off the device.

In practice, network devices don’t have a shutdown command, and reload typically just restarts the network OS.

Juniper recently launched their Tomahawk-based switch (QFX5200) and included a lot of information on the switching hardware in one of their public presentations (similar to what Cisco did with Nexus 9300), so I got a non-NDA glimpse into the latest Broadcom chipset.

You’ll get more information on QFX5200 as well as other Tomahawk-based switches in the Data Center Fabrics Update webinar in spring 2016.

Here’s what I understood the presentation said:

Do you want to know more about Cumulus Linux after learning what data center architectures it supports, what base technologies it uses, and how you can use it to simplify network configurations? It’s time to explore Cumulus Linux architecture (part 5 of the presentation Dinesh Dutt had during the Data Center Fabrics webinar).

I was really excited when Juniper announced Junos Fusion. I hoped for QFabric Done Right, but after watching the NFD10 video describing the architecture, I was disappointed: they reinvented Fabric Extenders.

The blog post was slightly updated on November 14th 2015 based on feedback received from Juniper engineers.

Many vendors talk about network automation these days, and almost all of them gloss over an important detail: automation works best when you manage to simplify things to the bare minimum needed to get the job done.

One of the vendors that focus on simplifying the network device configuration is Cumulus Linux.

I got into an interesting discussion with a fellow networking engineer trying to understand the impact of a switch failure in a L2/L3 data center fabric (anything from Avaya’s fabric or Brocade’s VCS Fabric to Cisco’s FabricPath, ACI or Juniper’s QFabric) on MAC and ARP tables.

Here’s my take on the problem – have I missed anything?

Dinesh Dutt started his part of the Data Center Fabrics Update webinar with “what is Cumulus Linux all about” and “what data center architectures does it support” and then quickly jumped into details about the base technologies used by Cumulus Linux: MLAG and IP routing.

Not surprisingly, the MLAG part generated tons of questions, and Dinesh answered all of them, even when he had to say “We don’t do that.”

After introducing the concepts of Cumulus Linux in the Data Center Fabrics update session, Dinesh Dutt described the typical data center architectures implemented with Cumulus Linux and the lessons everyone should learn from large-scale web properties.