What you'll learn:
- IP Routing vs. MPLS Forwarding
- Segment Routing Introduction
- ISIS Segment Routing Configuration for IPv4
- OSPF Segment Routing Configuration for IPv4
- ISIS Segment Routing Configuration for IPv6
- MPLS Data Plane Operation
- Simple and Efficient Transport of MPLS Services
- Segment Routing Global Block
- Label Switching Database (LSD)
- Segment Routing Co-existence with LDP
- Simple Migration from LDP to Segment Routing
- Interworking Deployment Model
- Segment Routing Topology Independent LFA
- Segment Routing Traffic Engineering
- Multi domain ODN with Path Computation Element (PCE)
Segment Routing (SR) is a flexible, scalable way of doing source routing. The source chooses a path and encodes it in the packet header as an ordered list of segments.
Segments are identifier for any type of instruction. Each segment is identified by the segment ID (SID) consisting of a flat unsigned 32-bit integer.
Segment instruction can be:
• Go to node N using the shortest path
• Go to node N over the shortest path to node M and then follow links Layer 1, Layer 2, and Layer 3
• Apply service S
With segment routing, the network no longer needs to maintain a per-application and per-flow state.
Instead, it obeys the forwarding instructions provided in the packet. Segment Routing relies on a small number of extensions to Cisco Intermediate System-to-Intermediate System (IS-IS) and Open Shortest Path First (OSPF) protocols.
It can operate with an MPLS (Multiprotocol Label Switching) or an IPv6 data plane, and it integrates with the rich multi service capabilities of MPLS, including Layer 3 VPN (L3VPN), Virtual Private Wire Service (VPWS), Virtual Private LAN Service (VPLS), and Ethernet VPN (EVPN).
Segment routing can be directly applied to the Multiprotocol Label Switching (MPLS) architecture with no change in the forwarding plane. Segment routing utilizes the network bandwidth more effectively than traditional MPLS networks and offers lower latency. A segment is encoded as an MPLS label.
