SPRING/SR refers to which routing concept?

• A. Source Routing
• B. Path Encoding Routing
• C. Segment Routing
• D. Policy Routing

Answer: (C)

Segment Routing is the concept behind SPRING. The key idea is that the sender encodes the entire end-to-end path directly into the packet as a sequence of segments, where each segment represents a routing instruction (such as a specific node or a sub-path). As the packet moves through the network, routers simply follow the topmost segment and forward accordingly, without needing per-flow state to be kept in the core devices. This makes routing scalable and flexible, because the path can be chosen by the source or network policy and embedded in the packet header.

SPRING can be implemented in two main data-plane ways: SR-MPLS, where segments are represented by an MPLS label stack, and SRv6, where an IPv6 extension header carries the list of segments. This explicit path encoding is what differentiates Segment Routing from more traditional routing approaches that rely on per-flow state in routers or policies evaluated at each hop.