IETF RFC 8302 PDF

This document describes mechanisms to optimize the Address Resolution Protocol (ARP) and Neighbor Discovery (ND) traffic in a Transparent Interconnection of Lots of Links (TRILL) campus. TRILL switches maintain a cache of IP / Media Access Control (MAC) address / Data Label bindings that are learned from ARP/ND requests and responses that pass through them. In many cases, this cache allows an edge Routing Bridge (RBridge) to avoid flooding an ARP/ND request by either responding to it directly or encapsulating it and unicasting it. Such optimization reduces packet flooding over a TRILL campus.