PIM Join Attributes for Locator/ID Separation Protocol (LISP) Environments

This document defines two PIM Join/Prune attributes that support the construction of multicast distribution trees where the root and receivers are located in different Locator/ID Separation Protocol (LISP) sites. These attributes allow the receiver site to select between unicast and multicast underlying transport, to convey the RLOC (Routing Locator) address of the receiver ETR (Egress Tunnel Router) to the control plane of the root ITR (Ingress Tunnel Router) and to signal the underlay multicast group to the control plane of the root ITR. This document updates RFC 8059 and RFC 9798.