FHRP OPTIMIZATIONS FOR N-WAY GATEWAY LOAD BALANCING IN FABRIC PATH SWITCHING NETWORKS

摘要

Techniques are disclosed for providing n-way gateway load-balancing in a fabric path switching Systems (FSS), such as a layer 2 multipath (L2MP) network in a large data center. An access switch in a L2MP network may learn an emulated switch IDs through FHRP “hello” messages sent by an “active” gateway router for each FHRP group. Further, the access switch may learn which links an emulated switch is reachable over by evaluating link state messages (e.g., IS-IS messages) sent by the gateway routers used to construct the emulated switch. Doing so allows the access switch to learn both the ID of an emulated switch and a set of links over which the emulated switch may be reached, thereby allowing the access switch to load balance traffic to the emulated switch.