Category: Virtualization

Years ago I managed to saturate a 10GE uplink on a vSphere server I tested with a single Linux VM using less than one vCPU. On the other hand, squeezing 1 Gbps out of Open vSwitch using GRE encapsulation was called ludicrous speed not so long ago. Implementing overlay virtual networking in the hypervisor obviously carries a huge performance penalty, right? Not so fast…

In the Myths That Refuse to Die: Scalability of Overlay Virtual Networking blog post I wrote “number of MAC addresses has absolutely no impact on the forwarding performance until the MAC hash table overflows”, which happens to be almost true.

When we started planning a VMware NSX-focused podcast episode with Dmitri Kalintsev, I asked my readers what topics they’d like to see covered. Two comments that we really liked were “how do I get started with VMware NSX?” and “how do I troubleshoot this stuff?”

Cloud builders are often using my ExpertExpress service to validate their designs. Tenant onboarding into a multi-tenant (private or public) cloud infrastructure is a common problem, and tenants frequently want to retain the existing network services appliances (firewalls and load balancers).

The Combine Physical and Virtual Appliances in a Private Cloud case study describes a typical solution that combines per-tenant virtual appliances with frontend physical appliances.

Simonp made a perfectly valid point in a comment to my latest OVS blog post:

Obviously the page you're referring to is a quick-and-dirty benchmark. If you wanted the optimal numbers, you would have to tune quite a few parameters just like for hardware benchmarks (sysctl kernel parameters, Jumbo frames, ...).

While he’s absolutely right, this is not the performance data a typical user should be looking for.

While the industry press deliberates the disaggregation of Arista and Cisco, and Juniper’s new CEO, Juniper launched a virtual version of its vMX router, which is supposed to have up to 160 Gbps of throughput (as compared to 10 Gbps offered by Vyatta 5600 and Cisco CSR). Can Juniper really deliver on that promise?

A while ago I wrote about performance bottlenecks of Open vSwitch. In the meantime, the OVS team drastically improved OVS performance resulting in something that Andy Hill called Ludicrous Speed at the latest OpenStack summit (slide deck, video).

Let’s look at how impressive the performance improvements are.

Stefan de Kooter (@sdktr) sent me a follow-up question to my Going All Virtual with Virtual WAN Edge Routers blog post:

How would one interface with external Internet in this scenario? I totally get the virtual network assets mantra, but even a virtual BGP router would need to get a physical interconnect one way or another.

As always, there are plenty of solutions depending on your security needs.

The pilot episode of Software Gone Wild podcast featuring Snabb Switch created plenty of additional queries (and thousands of downloads) – it was obviously time for another deep dive episode discussing the intricate innards of this interesting virtual switch.

During the deep dive Luke Gorrie, the mastermind behind the Snabb Switch, answered a long list of questions, including:

Nexus 1000V release 5.2(1)SV3(1.1) was published on August 22nd (I’m positive that has nothing to do with VMworld starting tomorrow) and I found this gem in the release notes:

Enabling BPDU guard causes the Cisco Nexus 1000V to detect these spurious BPDUs and shut down the virtual machine adapters (the origination BPDUs), thereby avoiding loops.

It took them almost three years, but we finally have BPDU guard on a layer-2 virtual switch (why does it matter). Nice!