Category: Virtualization

After introducing the fundamentals of Docker networking, Dinesh Dutt focused on various Docker networking options, including multi-host networking with overlays.

After watching the video, you might also want to listen to Episode 49 of Software Gone Wild with Brent Salisbury, Dave Tucker and Madhu Venugopal.

I got a long list of VXLAN-related questions from one of my subscribers. It started with an easy one:

Does Cisco ACI use VXLAN inside the fabric or is something else used instead of VXLAN?

ACI uses VXLAN but not in a way that would be (AFAIK) interoperable with any non-Cisco product. While they do use some proprietary tagging bits, the real challenge is the control plane.

I got into an interesting discussion with Johannes Luther on the need for VRFs and he wrote:

If VRF = L3 virtualization technologies, then I saw that link. However, VRFs are again just a tiny piece of the whole story.

Of course he’s right, but it turns out that VRFs are the fundamental building block of most L3 virtualization technologies using a shared infrastructure.

One of my readers sent me an interesting question a while ago:

Isn’t IS-IS a better fit for building L3-only networks than BGP, particularly considering that IS-IS already has a protocol to communicate with the end systems (ES-IS)?

In theory, he’s correct (see also this blog post).

After explaining the basics of Linux containers, Dinesh Dutt moved on to the basics of Docker networking, starting with an in-depth explanation of how a container communicates with other containers on the same host, with containers residing on other hosts, and the outside world.

We did several podcasts describing how one could get stellar packet forwarding performance on x86 servers reimplementing the whole forwarding stack outside of kernel (Snabb Switch) or bypassing the Linux kernel and moving the packet processing into userspace (PF_Ring).

Now let’s see if it’s possible to improve the Linux kernel forwarding performance. Thomas Graf, one of the authors of Cilium claims it can be done and explained the intricate details in Episode 64 of Software Gone Wild.

We got pretty far in our Data Center optimization journey. We virtualized the workload, got rid of legacy technologies, and reduced the number of server uplinks and replaced storage arrays with distributed file system.

Final step on the journey: replace physical firewalls and load balancers with virtual appliances.

Dinesh Dutt started his excellent Docker Networking webinar with introduction to the concepts of microservices and Linux containers. You won’t find any deep dives in this part of the webinar, but all you need to do to get the details you’re looking for is to fill in the registration form.

Does it make sense to run OpenStack on top of VMware infrastructure? How well does NSX work as a Neutron plug-in? Marcos Hernandez answered these questions (and a lot of others) in the Episode 61 of Software Gone Wild (admittedly after a short marketing pitch in the first 10 minutes).

One of my readers left this question on the blog post resurfacing the idea of running BGP between servers and ToR switches:

When using BGP on a VM for mobility, what is the best way to establish a peer relationship with a new TOR switch after a live migration? The VM won't inherently know the peer address or the ASN.

As always, the correct answer is it depends.