Hello Daniel
The EID is, by definition, always the IP address assigned to the host (e.g., 192.168.2.102 in the lesson). The EID remains static even if the host moves locations, while the RLOC changes dynamically to reflect the host’s new topological location.
In a sense yes. But the RLOC does not represent a next hop as a part of a series of next hops. It represented the location of the intended destination host. There is only one RLOC, whereas there are a whole series of next hops to get to the destination in traditional routing.
The role of a router as an ITR or an ETR depends on the context. For example, R1 is an ITR for Site 1 for all outgoing traffic. It is however an ETR for all of the addresses within Site 1. So it plays the role of both. For traffic going in the direction of Site 1–> Site 2, the ETR is R2 at Site 2, because those are the destination IP addresses we want to use. You can choose to configure one router to play both roles, or you can separate the roles to different devices.
I think I answered this question above. There is an ETR for each LISP site which informs the mapping database system of the EIDs that it serves.
I hope this has been helpful!
Laz