China Mobile Huawei Technologies China Mobile ZTE Corporation China Mobile The Segment Routing over IPv6 (SRv6) Network Programming framework enables a network operator or an application to specify a packet processing program by encoding a sequence of instructions in the IPv6 packet header. Following the SRv6 Network Programming concept, this document defines SRv6 based mechanisms for inter-layer network programming, which can help to integrate the packet network layer with its underlying layers efficiently. For inter-layer path programming, a new SRv6 behavior is defined for steering packets to underlay network connections. The applicability of this new SRv6 behavior in typical scenarios is illustrated.