Tuesday, August 31, 2021

Netdev 0x15

The recent Netdev 0x15 conference included a number of papers diving into the technology behind Linux as a network operating system. Slides and videos are now available on the conference web site.
Network wide visibility with Linux networking and sFlow describes the Linux switchdev driver used to integrate network hardware with Linux. The talk focuses on network telemetry, showing how standard Linux APIs are used to configure hardware instrumentation and stream telemetry using the industry standard sFlow protocol for data center wide visibility.
Switchdev in the wild describes Yandex's experience of deploying Linux switchdev based switches in production at scale. The diagram from the talk shows the three layer leaf and spine network architecture used in their data centers. Yandex operates multiple data centers, each containing up to 100,000 servers.
Switchdev Offload Workshop provides updates about the latest developments in the switchdev community. 
FRR Workshop discusses the latest development in the FRRouting project, the open source routing software that is now a defacto standard on Linux network operating systems.

Wednesday, August 18, 2021

Nokia Service Router Linux

Nokia Service Router Linux (SR-Linux) is an open source network operating system running on Nokia's merchant silicon based data center switches.

The following commands configure SR-Linux to sample packets at 1-in-10000, poll counters every 20 seconds and stream standard sFlow telemetry to an analyzer ( using the default sFlow port 6343:

system {
    sflow {
        admin-state enable
        sample-rate 10000
        collector 1 {
            network-instance default
            port 6343

For each interface:

interface ethernet-1/1 {
    admin-state enable
    sflow {
        admin-state enable

Enable sFlow on all switches and ports in the data center fabric for comprehensive visibility.

An instance of the sFlow-RT real-time analytics software converts the raw sFlow telemetry into actionable measurements to drive operational dashboards and automation (e.g. DDoS mitigation, traffic engineering, etc.).
docker run --name sflow-rt -p 8008:8008 -p 6343:6343/udp -d sflow/prometheus
A simple way to get started is to run the Docker sflow/prometheus image on the sFlow analyzer host ( in the example config) to run sFlow-RT with useful applications to explore the telemetry. Access the web interface at