Explains how SRv6-TE policies steer traffic along intent-based paths and provides the tools needed to control, protect, monitor, and troubleshoot those paths.
This chapter introduces Segment Routing over IPv6 Traffic Engineering (SRv6-TE), a solution designed to provide granular control and flexibility in managing network traffic.
SRv6-TE enables administrators to steer traffic across IPv6 networks according to specific policies and requirements, facilitating the creation of explicit paths for applications demanding particular Quality of Service (QoS) levels, such as low latency or high bandwidth.
SRv6-TE offers significant advantages over traditional methods like MPLS RSVP-TE, including enhanced scalability, reduced complexity, optimized resource utilization through ECMP, and seamless integration with existing IPv6 infrastructure. It supports advanced traffic engineering capabilities, dynamic path computation, and explicit path configurations, making it essential for modern, agile networks.
Segment Routing over IPv6 Traffic Engineering (SRv6-TE)
Explains how SRv6-TE uses SIDs in the SRH to steer traffic through explicit or dynamically calculated paths and identifies its supported policy capabilities.
SRv6-TE Policy
Explains how candidate paths, segment lists, constraints, metrics, and protection requirements determine the path selected by an SRv6-TE policy.
Explicit Paths
Explains how explicit SRv6-TE paths use predefined uSIDs and SID carriers to provide deterministic forwarding, policy enforcement, predictable performance, resource optimization, and failover.
Dynamic Paths
Explains how headends compute and recompute dynamic SRv6-TE paths using hop-count, IGP, TE, or delay objectives together with affinity, disjointness, and protection constraints.
Segment Protection-Type Constraint
Describes how protected-only, protected-preferred, unprotected-only, and unprotected-preferred constraints control SID-list encoding and TI-LFA coverage for dynamic SRv6-TE candidate paths.
SRv6 Per-Flow next-hop redirection using ABF
Explains how ABF redirects selected IPv4 or IPv6 flows to SRv6-reachable next hops without requiring explicit SR policies and describes its restrictions and configuration.
SRv6 Flexible Algorithm
Describes how Flex-Algo creates SLA-specific network slices and steers VPN traffic over paths optimized for cost, delay, or other IGP constraints.
SRv6 policy counters
Explains how policy, candidate-path, segment-list, and interface counters support traffic monitoring, policy validation, troubleshooting, capacity planning, and forwarding verification.
SRv6-TE explicit BSIDs and remote steering
Explains how explicit BSIDs provide stable policy identification and allow remote nodes to steer traffic into SRv6-TE policies, including associated configuration guidelines and limitations.