Extended Mobility Procedures for EVPN-IRB

Procedure to handle host mobility in a layer 2 Network with EVPN control plane is defined as part of RFC 7432. EVPN has since evolved to find wider applicability across various IRB use cases that include distributing both MAC and IP reachability via a common EVPN control plane. MAC Mobility procedures defined in RFC 7432 are extensible to IRB use cases if a fixed 1:1 mapping between VM IP and MAC is assumed across VM moves. Generic mobility support for IP and MAC that allows these bindings to change across moves is required to support a broader set of EVPN IRB use cases, and requires further consideration. EVPN all-active multi-homing further introduces scenarios that require additional consideration from mobility perspective. This document enumerates a set of design considerations applicable to mobility across these EVPN IRB use cases and defines generic sequence number assignment procedures to address these IRB use cases.