Blog Posts in April 2016
After listening to Open-Source Network Engineer Toolbox Nick Buraglio sent me an email saying “we should do another podcast on open-source network management tools…” and so we did. In Episode 56 of Software Gone Wild Nick, Elisa Jasinska and myself discussed a whole range of network management challenges and open-source tools you can use to address them.
One of my readers sent me this observation while reviewing my BGP-Based SDN Solutions webinar:
I am a bit surprised the SDN controller can actually be so lightweight.
Well, that's the benefit of augmenting an existing well-developed ecosystem instead of reinventing the wheel and reimplementing every single bit of functionality we had to develop to make networks work throughout the last 5 decades.
A month ago I published the video where I described the idea that “two switches is all you need in a medium-sized data center”. Now let’s dig into the details: the first step you have to take to optimize your data center infrastructure is to virtualize all servers.
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I got an interesting question from one of my readers:
If every device talking to a centralized control plane uses an out-of-band channel to talk to the OpenFlow controller, isn’t this a scaling concern?
A year or so ago I would have said NO (arguing that the $0.02 CPU found in most networking devices is too slow to overload a controller or reasonably-fast control-plane network).
Strange how inter-DC clustering failure is considered a certainty in this blog.
Call it experience or exposure to a larger dataset. Anything you build will eventually fail; just because you haven’t experienced the failure yet doesn’t mean that the system will never fail but only that you were lucky so far.
When I started thinking about my first online course, I decided to create something special – it should be way more than me talking about cool new technologies and designs – and the guest speakers are a crucial part of that experience.
The first guest speaker is one of the gurus of network design and complexity, wrote numerous books on the topic, and recently worked on a hardware-independent network operating system.
Russ White wrote a great response to my “Do You Really Want to Write that Book?” blog post and I couldn’t agree more with what he wrote. Unfortunately, he seems to be a bit over-idealistic when analyzing why the market for high-end content is so small.
You know I usually have a cynical explanation handy, so here it is: too many people calling themselves engineers for no particular reason simply don’t care. It’s way easier to Google-and-paste your way around than to invest time in understanding the fundamentals.
Oliver Steudler from Juniper sent me a link to an interesting Juniper blog post describing zero-bandwidth traffic engineering.
Read the blog post first and then come back for some opinionated rambling ;)
Is the problem real? Yes.
A few months ago I met a number of great engineers from Avaya and they explained to me how they creatively use Shortest Path Bridging (SPB) to create layer-2, layer-3, L2VPN, L3VPN and even IP Multicast fabrics – it was clearly time for another deep dive into SPB.
It took me a while to meet again with Roger Lapuh, but finally we started exploring the intricacies of SPB, and even compared it to MPLS for engineers more familiar with MPLS/VPN. Interested? Listen to Episode 54 of Software Gone Wild.
During one of my Network Automation workshops one of the attendees said: “Why are you using open-source software? It’s so poorly documented and impossible to set up.”
I totally understood what he was trying to say (I’ve seen too many examples of just read the code approach), but fortunately there are still people who understand the value of documentation.
Continuing our routing-on-hosts discussions, Enno Rey (of the Troopers and IPv6 security fame) made another interesting remark “years ago we were so happy when we finally got rid of gated on Solaris” and I countered with “there are still people who fondly remember the days of running gated on Solaris” because it’s a nice solution to host-to-network multihoming problem.
Quoting RFC1925, “It’s easier to move a problem around than to solve it” and people have been extremely good at moving this particular problem around for decades.
After I told you that I’m not going to Interop, I got numerous emails along the lines of “but I was really looking forward to attending your workshop” so I started looking for a solution that would combine the best of online and classroom worlds.
Here’s my first attempt: an interactive online course combining topics from two of my Interop workshops. I’m still working on the detailed agenda and plan to have it ready around May 1st. In the meantime, I’d really appreciate your feedback – leave a comment or send me an email.
Luka Manojlovič, a networking engineer with strong focus on Windows and IPv6 sent me a short status update on an enterprise IPv6 deployment:
Moved a whole enterprise network (central location + 17 remote locations) to dual-stack today. So far everything works.
While that sounds pretty easy, there was a lot of work going on behind the scenes. Here are some of the highlights:
Russ White made an excellent remark while discussing the news that the CloudRouter pushed 650 Gbps through commodity hardware: “If this is software defined networking, then we’ve been doing this since sometime in the 1990’s, perhaps even earlier…”
He’s absolutely right – the first routers (like AGS or IGS from Cisco) did all packet forwarding in software, so as I explained during the Introduction to SDN webinar while reaching dozens of gigabits with software-based packet forwarding is exciting, calling it SDN doesn’t make much sense.
Everyone loves to talk about business critical applications that require extremely high availability, but it’s rare to see someone analyze the whole application stack and identify the weakest link.
For more details, watch my Designing Active/Active and Disaster Recovery Data Centers or attend one of my workshops.
If you start mapping out the major components of an application stack, you’ll probably arrive at this list (bottom-to-top):
Hope you’ll enjoy the talk; for more SDN use cases watch the SDN Use Cases webinar.
A while ago Christer Swartz explained how a Palo Alto firewall integrates with VMware NSX. In the meantime, Palo Alto announced integration with Cisco ACI and OpenStack, and it was time for another podcast with Christer deep-diving into the technical details of these integrations.