Best answer by Stephane Grosjean
I'd not configure ELRP on a Core switch (or just for logs to see the loops happening). This is a Edge protection. You should configure it at the edge, excluding the uplinks, and use egress for optimisation if you also do not configure ELRP on uplinks (not sending ELRP PDUs to the Core).
Egress is just defining what port to shutdown when a loop is detected : is it the one that generates it, or the one that received it?