In the early 2010s, Linux had already begun conquering data centers, and it was on the path to becoming the standard operating system for servers. At the same time, another data center trend emerged: Virtualization. To keep pace with the development of virtualized infrastructures, networks had to go virtual, too.

Software-defined networks (SDNs) were the first step toward network virtualization. The Open Networking Foundation was founded in 2011 to further disseminate and standardize SDNs. Open vSwitch found its way into the kernel in 2012, the same year that VMware bought SDN pioneer Nicira. The pace of development was fast – too fast for the Linux kernel. Network technology requires high performance, which for Linux means that it must be part of the kernel. Code changes to the kernel often take many months, and after a release, they are slow to reach the distributions as packages. This slow pace of change slowed the adoption of rapidly developing network technologies. At the same time, the first container solutions appeared, placing even more demands on the network. A new approach was needed.

eBPF Revolutionizes Linux

Alexei Starovoitov found a solution: He expanded the existing BPF kernel subsystem, which was quite simple at the time and had been developed in the 1990s as a simple packet filter Starovoitov extended BPF to include some foundational capabilities, launching eBPF [1] in the process.

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