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

Examining Open vSwitch Traffic Patterns

In this post, I want to provide some additional insight on how the use of Open vSwitch (OVS) affects—or doesn’t affect, in some cases—how a Linux host directs traffic through physical interfaces, OVS internal interfaces, and OVS bridges. This is something that I had a hard time understanding as I started exploring more advanced OVS configurations, and hopefully the information I share here will be helpful to others.

(Read more...)

Using pf on OS X Mountain Lion

I’ve written before about adding an extra layer of network security to your Macintosh by leveraging the BSD-level ipfw firewall, in addition to the standard GUI firewall and additional third-party firewalls (like Little Snitch). In OS X Lion and OS X Mountain Lion, though, ipfw was deprecated in favor of pf, the powerful packet filter that I believe originated on OpenBSD. (OS X’s version of pf is ported from FreeBSD.) In this article, I’m going to show you how to use pf on OS X.

(Read more...)

Joint OpenStack Denver and Infracoders Denver Meetup

Next Monday, May 20, the OpenStack Denver meetup group will gather jointly with the inaugural meeting of the Infracoders Denver meetup group for a talk titled “Infrastructure as Code with Chef and OpenStack.” The joint meeting will be held at Innovation Pavilion in Centennial/Englewood (location information here). The event will start at 7PM.

(Read more...)

Using GRE Tunnels with Open vSwitch

I’m back with another “how to” article on Open vSwitch (OVS), this time taking a look at using GRE (Generic Routing Encapsulation) tunnels with OVS. OVS can use GRE tunnels between hosts as a way of encapsulating traffic and creating an overlay network. OpenStack Quantum can (and does) leverage this functionality, in fact, to help separate different “tenant networks” from one another. In this write-up, I’ll walk you through the process of configuring OVS to build a GRE tunnel to build an overlay network between two hypervisors running KVM.

(Read more...)

Very Early Thoughts about EMC ViPR

EMC announced ViPR today, the culmination of the not-so-secret Project Bourne and its lesser-known predecessor, Project Orion. Although I used to work at EMC before I joined VMware earlier this year, I never really had deep access to what was going on with this project, so my thoughts here are strictly based on what’s been publicly disclosed. Naturally, given that the product was only announced today, these are very early thoughts.

(Read more...)

Technology Short Take #32

Welcome to Technology Short Take #32, the latest installment in my irregularly-published series of link collections, thoughts, rants, raves, and miscellaneous information. I try to keep the information linked to data center technologies like networking, storage, virtualization, and the like, but occasionally other items slip through. I hope you find something useful.

(Read more...)

Potential Fix for Kerberos, SSH, LDAP, and Active Directory Issue

I had a reader contact me with a question on using Kerberos and LDAP for authentication into Active Directory, based on Active Directory integration work I did many years ago. I was unable to help him, but he did find the solution to the problem, and I wanted to share it here in case it might help others.

(Read more...)

Spousetivities at IBM Edge 2013

Regular readers of this site know that my wife, Crystal, runs something called Spousetivities. Spousetivities originated out of boredom, essentially—Crystal was traveling with me to VMworld and wanted to find someone to hang out with while I was at the conference. That was VMworld 2008, and since that time she’s had activities at VMworld 2009, VMworld 2010 (including VMworld Europe 2010), VMworld 2011 (both US and Europe), and VMworld 2012 (US and Europe). She’s also had activities at EMC World (2011 and 2012), HP Discover EMEA, and Dell Storage Forum in Boston. This year, she’s added another conference: IBM Edge 2013 in Las Vegas!

(Read more...)

On Network Virtualization and SDN

Is there a difference between network virtualization and Software-Defined Networking (SDN)? If so, what is the relationship between them? Is one a subset of the other? This is a topic that is increasingly being discussed and debated. So, in a similar fashion to my post on network overlays vs. network virtualization, I thought I’d weigh in with some thoughts. This post, like all of my posts, is intended to help spark a conversation, so I encourage you to share your thoughts in the comments after you’ve finished reading.

(Read more...)

Collection of OpenStack Summit Session Liveblogs

I had the pleasure of attending the OpenStack Summit in Portland, OR last week. It was my first time at the OpenStack Summit, and it was great to meet lots of folks in the OpenStack community as well as be exposed to some more in-depth and detailed OpenStack information. While I was there I tried to liveblog as many sessions as I was able; here are links to the various session liveblogs that I managed to publish. Enjoy!

(Read more...)