What Is Segment Routing?

A method of forwarding packets based on source routing where the routing path is encoded in the packet header as an ordered list of segments. This means traffic can be forwarded selecting any routing path and not just the Interior Gateway Protocol (IGP) shortest path. It also supports automatic traffic protection for node and link failures by Topology-Independent Loop-Free Alternates (TI-LFA).

Contact Cisco

Why Segment Routing?

It enables granular traffic control without the need for additional protocols like when deploying MPLS TE. In addition, it does not require any path signaling, making it highly scalable.

What does that mean for me?

Segment routing simplifies the network by removing protocols and automating operations. Granular traffic control allows you to achieve a higher level of bandwidth utilization without impacting resiliency. Network resiliency is achieved with 50ms restoration of connectivity. New value added services can be provisioned into the network without necessarily adding hardware and bandwidth.

How do I use Segment Routing?

Segment Routing can be deployed natively on an MPLS or IPv6 data plane. It can also be deployed in conjunction with an existing LDP network. Segment Routing can be configured in a variety of Cisco products including the 8000 Series, ASR 9000, NCS 5500/5700, NCS 540/560.

What about SRv6?

SRv6 refers to Segment Routing over IPv6 dataplane and refers to the concept of network programming expressed as a list of instructions (Segment ID).

Segment Routing Resources

Cisco Segment Routing Configuration Guides

Case Studies