Segment Routing over IPv6 (SRv6) simplifies network engineering by encoding forwarding instructions directly into IPv6 extension headers, eliminating the need for MPLS label stacks and the associated LDP and RSVP-TE signaling protocols. This approach aligns network programmability with modern software-defined principles.
SRv6 Architecture and Benefits
SRv6 uses the IPv6 Segment Routing Header to carry an ordered list of segments, where each segment identifies a network instruction such as forwarding to a specific node, traversing a particular link, or applying a service function. The network function abstraction provided by SRv6 Network Programming enables traffic engineering, VPN services, and service chaining with a single protocol.
Major service providers including SoftBank, China Mobile, and Bell Canada have deployed SRv6 at scale, reporting significant operational simplification from reducing the number of control plane protocols. The transition from MPLS to SRv6 eliminates the need for separate labels and tunnels, reducing router state and simplifying troubleshooting.
For data center operators, SRv6 enables seamless connectivity between sites with native IPv6 underlay, supports multi-tenancy with per-VPN SID lists, and integrates with intent-based networking controllers for policy-driven path selection and load balancing across the WAN.