SRv6 Network Programming in Linux Kernel


Stefano Salsano
Reshma Sudarshan
Daniel Bernier
Ahmed Abdelsalam


Nuts and Bolts

Session Type




The Segment Routing over IPv6 (SRv6) Network Programming framework enables a network operator or an application to specify a packet processing program by encoding a sequence of instructions in the IPv6 packet header. The SRv6 Network Programming framework is standardized in IETF RFC8986.

SRv6 has been supported in the Linux kernel since its introduction at IETF. The very first support of SRv6 in the Linux kernel was introduced in release 4.10 (almost 6 years old now) [1].

Since then, SRv6 support in the Linux kernel has been getting more mature with almost each kernel release. New features, bug fixes and performance improvement patches are getting merged in the Linux kernel over time. An excerpt of SRv6 related patches submitted to the Linux kernel over the last years is shown in [2]. Currently, the Linux kernel supports most of the SRv6 Network programming behaviors defined in IETF RFC8986.

SRv6 leverages the lightweight tunnel of the Linux Kernel. It defines two new lightweight tunnels names seg6 and seg6local. The SRv6 support extends to other sub-systems including Netfilter, eBPF, and others.

The mature support of SRv6 in the Linux kernel has enabled many use-cases. Indeed, many open-source stacks has been updated to support SRv6 and leverage the SRv6 support in the Linux kernel. These stacks include FRR, Cilium, and SONiC.

  • FRR currently supports several SRv6 features including L3VPN services. These services leverage the SRv6 dataplane (encapsulation and decapsulation) behaviors supported in the Linux kernel. The SRv6 support in FRR is across several daemons including Zebra, BGP, SHARP.
  • Cilium provides a SRv6-based container networking leveraging the Linux kernel eBPF framework. The SRv6 extension Cilium aims to support telco networking requirements in a cloud-native way.
  • SONiC is an open-source network operating system (NOS) based on Linux. SONiC builds up on the SRv6 support in the Linux and FRR to provide a scalable solution for routing services and policies [3].


Monday 24th October, 15:30 WEST

  • SRv6 update Ahmed Abdelsalam (Cisco Systems)

  • ROSE (Research on Open Stefano Salsano (Univ. of SRv6 Ecosystem) update Rome Tor Vergata/CNIT)

  • Linux Kernel update Andrea Mayer (Univ. of Rome Tor Vergata/CNIT)

  • Cilium/eBPF Daniel Bernier (Bell Canada)

  • SONiC Resham Sudarsan (Intel)

  • FRR Carmine Scarpitta (Univ. of Rome Tor Vergata/CNIT)

In the workshop we will give an update to the netdev community on the SRv6 support in the Linux Kernel. We will review the supported SRv6 features, and associated iproute2 extension, starting from kernel 4.10 up to now. Also, we will provide an update on some new SRv6 features that we plan to contribute to the Linux Kernel. In addition, we will review the supported SRv6 features in FRR along with some interesting SRv6 control plane features that we plan to submit to FRR. Moreover, we will give an update on the SRv6 activities in Linux related open-source stacks such as SONiC and Cilium.