Related Topics; Overview Of Segment Routing - Cisco ASR 9000 Series Configuration Manuallines

L2VPN Services over Segment Routing for Traffic Engineering Policy
EVI Ethernet Segment Id EtherTag Nexthop Label SRTE IFH
----- ------------------------ -------- --------------------------------------- --------
----------
2 0000.0000.0000.0000.0000 1 205.3.0.3 24000 0x5a0
Source: Remote, MPLS
Associated Commands
• adjacency-sid
• index
• prefix-sid
• router isis
• segment-routing
The applicable segment routing commands are described in the Segment Routing Command Reference for
Cisco ASR 9000 Series Routers

Related Topics

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Overview of Segment Routing

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. An ordered
Overview of Segment Routing , on page 665
How Segment Routing Works , on page 666
Segment Routing Global Block , on page 667
L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers, IOS XR Release 6.3.x
Associated Commands
665