Category: Workshop

Building Large L3 Fabrics with Brocade VDX Switches

Update 2021-01-03: VDX switches were an interesting bit of hardware. They died of boredom a few years ago, Brocade started using merchant silicon in their Ethernet switches, and then that part of the company got acquired by Extreme. The whole VCS Fabric idea was sent to the graveyard when Brocade Product Management discovered VXLAN and EVPN.

A few days ago the title of this post would be one of those “find the odd word out” puzzles. How can you build large L3 fabrics when you have to work with ToR switches with no L3 support, and you can’t connect more than 24 of them in a fabric? All that has changed with the announcement of VDX 8770 – a monster chassis switch – and new version of Brocade’s Network OS with layer-3 (IP) forwarding.

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QFabric Behind the Curtain: I was spot-on

A few days ago Kurt Bales and Cooper Lees gave me access to a test QFabric environment. I always wanted to know what was really going on behind the QFabric curtain and the moment Kurt mentioned he was able to see some of those details, I was totally hooked.

Short summary: QFabric works exactly as I’d predicted three months before the user-facing documentation became publicly available (the behind-the-scenes view described in this blog post is probably still hard to find).

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Is Layer-3 Switch More than a Router?

Very short answer: no.

You might think that layer-3 switches perform bridging and routing, while routers do only routing. That hasn’t been the case at least since Cisco introduced Integrated Routing and Bridging in IOS release 11.2 more than 15 years ago. However, Simon Gordon raised an interesting point in a tweet: “I thought IP L3 switching includes switching within subnet based on IP address, routing is between subnets only.”

Layer-3 switches and routers definitely have to perform some intra-subnet layer-3 functions, but they’re usually not performing any intra-subnet L3 forwarding.

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802.1BR – same old, same old

A while ago, a tweet praising the wonders of 802.1BR piqued my curiosity. I couldn’t resist downloading the latest draft and spending a few hours trying to decipher IEEE language (as far as the IEEE drafts go, 802.1BR is highly readable) ... and it was déjà vu all over again.

Short summary: 802.1BR is repackaged and enhanced 802.1Qbh (or the standardized version of VM-FEX). There’s nothing fundamentally new that would have excited me.

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VMware buys Nicira: a Hypervisor Vendor Woke Up

Almost a year ago, I predicted that eventually the hypervisor vendors will wake up and realize it’s time to get rid of VLANs and decouple virtual networks from the physical world. We’ve got the first glimpse of the brave new world a few weeks after that post was published with the VXLAN launch, but that was still a Cisco’s solution running on top of VMware’s (and now everyone else’s) hypervisor. The recent VMware’s acquisition of Nicira proves that VMware finally woke up big time.

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Analyst-driven IPv6 deployment

Straight from the rumor mill (source, translated):

One of German ISPs is actually quite busy rolling out IPv6 after their CFO got a call from a stock analyst right during the RIPE meeting, asking questions “so what are your IPv6 plans?” – “none, what is IPv6?” – “oh, this is not so good”… full panic down the management chain…

Proves the everlasting wisdom from Martin Levy (source, the rest of article is not worth reading):

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