Which Cisco Locator/ID Separation Protocol (LISP) device receives packets from remote site facing devices and either decapsulates the LISP packets or routes them natively?

An Ingress Tunnel Router (ITR) is responsible for encapsulating native IP packets with a LISP header and sending them to remote ETRs, not for receiving and decapsulating.

An Egress Tunnel Router (ETR) is a LISP device responsible for receiving LISP-encapsulated IP packets from remote LISP sites. It then decapsulates these packets and forwards the original inner IP packets to their ultimate destinations within its local site, or routes them natively if the destination is local and not LISP-mapped.

A Map Server (MS) stores the mappings between Endpoint IDs (EIDs) and Routing Locators (RLOCs) and responds to Map-Requests from Map Resolvers.

A Map Resolver (MR) receives Map-Requests from ITRs and forwards them to the appropriate Map Server to find an EID-to-RLOC mapping.