Category: Software Gone Wild

A while ago I started discussing the intricate technical details of fibbing (an ingenious way of implementing traffic engineering with traditional OSPF) with Laurent Vanbever and other members of his group, and we decided to record a podcast on this topic.

Things never go as planned in a live chat, and we finished talking about another one of his projects – software defined Internet exchange point (SDX), the topic of Episode 41 of Software Gone Wild.

When I asked “Are there any truly QoS-aware routing protocols out there?” in one of my SD-WAN posts, Marcelo Spohn from ADARA Networks quickly pointed out that they have one – Dynamic Link-State Routing Protocol.

He also claimed that DLSP has no scalability concerns – more than enough reasons to schedule an online chat, resulting in Episode 40 of Software Gone Wild. We didn’t go too deep this time, but you should get a nice overview of what DLSP is and how it works.

::: jump-link Enjoy the podcast :::

How do you capture all the flows entering or exiting a data center if your core Nexus 7000 switch cannot do it in hardware? You take an x86 server, load nProbe on it, and connect the nProbe to an analysis system built with ELK stack… at least that’s what Clay Curtis did (and documented in a blog post).

Obviously I wanted to know more about his solution and invited him to the Software Gone Wild podcast. In Episode 39 we discussed:

With the advent of layer-3 leaf-and-spine data center fabrics, it became (almost) possible to build pure layer-3-only data center networks… if only the networking vendors would do the very last step and make every server-to-ToR interface a layer-3 interface. Cumulus decided to do just that.

Writing OpenFlow controllers that interact with physical hardware is harder than most people think. Apart from developing a distributed system (which is hard in itself), you have to deal with limitations of hardware forwarding pipelines, differences in forwarding hardware, imprecise abstractions (most vendors still support single OpenFlow table per switch), and resulting bloated flow tables.

Elisa Jasinska, Bob McCouch and I were scheduled to record a NetOps podcast with a major vendor, but unfortunately their technical director cancelled at the last minute. Like good network engineers, we immediately found plan B and focused on Elisa’s specialty: open-source tools.

What happens when network engineers with strong programming background and focus on open source tools have to implement network automation in a multi-vendor network? Instead of complaining or ranting about the stupidities of traditional networking vendors and CLI they write an abstraction layer that allows them to treat all their devices in the same way and immediately open-source it.

A while ago Chris Young sent me a few questions about network management in the brave new SDN world. I never focused on network management, but I know a few people who do, including Terry Slattery and Matt Oswalt. Interop brought us all together, and we sat down one evening after the presentations to chat about the challenges of monitoring and managing SDN networks.

We started with easy things like comparing monitoring results from virtual and physical switches (and why they’ll never match and do we even care), and quickly diverted into all sorts of potential oscillations caused by overly-dynamic load balancing caused by flow label-based ECMP and flowlets.

With all the hype around Segment Routing we said: “let’s chat about it, what could possibly go wrong”. The result: Episode 33 of Software Gone Wild. We didn’t get very far into the technical details, but you might still find the overview useful (or not – do tell me how good or useless it is).

When preparing for my Simplifying Application Workload Migration workshop (coming in webinar format in autumn) I tried to find a solution that would allow me to recreate existing enterprise virtual network infrastructure in a cloud environment. Soon I stumbled upon Ravello Systems, remembered hearing about them on a CloudCast.net podcast, and got in touch with them to figure out whether they could help me solve that challenge.

It turned you might use Ravello Systems’ solution to implement disaster recovery, but I got way more excited about the possibility to use their solution for labs or testing. To learn more about that, listen to Episode 32 of Software Gone Wild.

When I finished my SDN workshop @ Interop Las Vegas (including a chapter on OpenFlow limitations), some attendees started wondering whether they should even consider OpenFlow in their SDN deployments. My answer: don’t blame the tool if people use it incorrectly.

Two days later, I discovered HP is one of those companies that knows how to use that tool.

Whenever software switching nerds get together and start discussing the challenges of high-speed x86-based switching, someone inevitably mentions PF_RING, an open-source library that gives you blazingly fast packet processing performance on a Linux server.

I started recording a podcast with Luca Deri, the author of PF_RING, but we diverted into discussing ntopng, Luca’s network monitoring software. We quickly fixed that and recorded another podcast – this time, it’s all about PF_RING, and we discussed these topics:

DNS is a crucial component in modern scale-out application architectures, so when Alex Vayl and Kris Beevers from NSONE contacted me just as I was starting to work on my Active-Active Data Centers presentation, I was more than interested to hear what their solution can do.

The result: Episode 29 of Software Gone Wild in which we discussed a number of topics including:

PF_RING is a great open-source project that enables extremely fast packet processing on x86 servers, so I was more than delighted when Paolo Lucente of the pmacct fame introduced me to Luca Deri, the author of PF_RING.

When we started chatting, we couldn’t resist mentioning ntopng, another open-source project Luca is working on.

VM NIC firewalls have been around for years (they’re also the reason I got my first invitation to the awesome Troopers conference), but it sounds so much better when you call them Microsegmentation (not the one I talked about @ Troopers this year).

Marketing gimmicks aside, VMware NSX includes an interesting in-kernel stateful firewall, and Brad Hedlund was kind enough to explain the intricacies of that feature in Episode 27 of Software Gone Wild