Scott's Weblog The weblog of an IT pro specializing in virtualization, networking, open source, and cloud computing

Revisiting VXLAN and Layer 3 Connectivity

In my earlier post on VXLAN and Layer 3 connectivity, I had a fatal flaw in my thinking and in my diagrams that was corrected for me in the comments to that post. In this post, I want to revisit the idea of Layer 3 connectivity with VXLAN and include the corrected information (and new diagrams).

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Fixing Repeating iTunes Firewall Prompt

As part of a comprehensive security strategy for my Mac—I don’t believe that Macs are automatically invulnerable to security threats—I use multiple host-based firewalls, including the Mac OS X application-level firewall found in System Preferences (this is in addition to Little Snitch and ipfw). However, recently I started noticing that every time I launched iTunes, it would prompt me for whether or not I wanted to allow iTunes to accept incoming network connections.

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Examining VXLAN

It’s taken me far too long to write this post, that’s for sure. Since the announcement of VXLAN at VMworld earlier in the year, I’ve been searching for additional information on these questions: “What is VXLAN? How does it fit into the broader networking landscape? Why did we need a new standard?” I talked to Cisco, I attended a VMworld session about networking futures, I talked to some of the authors of the IETF draft on VXLAN, I read (most of) the VXLAN draft, and I studied some existing protocols that one might think could have been put to use. I think I’m finally ready to try to address these questions.

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Some Initial MPLS Reading

I mentioned on Twitter yesterday that I was doing some basic/introductory reading on MPLS, and someone asked what materials I was using. While I’m still very early in the process of trying to understand MPLS, I thought I might share the resources I’ve used so far in trying to wrap my head around MPLS, what it is, and the basics of how it works.

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VXLAN and Layer 3 Connectivity

Note: I’ve posted a follow-up to this article with some corrected information. Please read here.

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Setting up Software FCoE on vSphere 5

One of the features added in vSphere 5 was a software FCoE initiator. This is a feature that has gotten relatively little attention, other than a brief mention here and there. I’m not entirely sure why the software FCoE initiator in vSphere 5 hasn’t gotten more attention, but this past week I had the opportunity to work with the software FCoE initiator in a bit more detail. In this post I’m going to describe in a bit more detail how to set up the software FCoE initiator; in future posts, I hope to be able to provide some performance and troubleshooting information.

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Technology Short Take #17

Welcome to Technology Short Take #17, another of my irregularly-scheduled collections of various data center technology-related links, thoughts, and comments. Here’s hoping you find something useful!

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Problem with VMXNET3 Driver

A colleague on the EMC vSpecialist team (many of you probably know Chris Horn) sent me this information on an issue he’d encountered. Chris wanted me to share the information here in the event that it would help others avoid the time he’s spent troubleshooting this issue.

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Giving Thanks on Thanksgiving

Here in the United States we are preparing to celebrate the Thanksgiving holiday, and it’s a time of reflection. It’s a time to be thankful for what we have and what we’ve been given. This past year has been a tremendous year for me, both personally and professionally, with lots of things for which to be thankful:

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Some OSS with my Mac, Part 2: Unison

(This is Part 2 of a two-part series on some open source software I’ve incorporated into my primarily Mac-based home office setup. Read Part 1.)

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