When a new technology like Segment Routing is introduced, in most cases it is perceived as a paradigm shift where its deployment is a complex matter which needs an architectural design review. One of the most interesting feature of the Segment Routing is how it has been developed, from one hand it reduces the control-plane complexity by leveraging the IGP routing protocols as label signaling protocols. On the other hand the MPLS forwarding plane remains more or less untouched.
In this second part of “Introduction to Segment Routing” we will take a look how the SR deals with MPLS forwarding-plane, which operations are applied to the labels and how both LDP and SR data-planes can coexist in the same network.
This is an additional factor to start evaluating to introduce easily Segment Routing in your network, leaving the LDP signaling active. It allows a gradual smooth introduction of Segment Routing, enabling it only where it is possible and verifying the correct segment-ID allocation first and then define a plan to enable Segment Routing preferred labelling.
Click here to read Introduction to Segment Routing Part I