Source MAC based routing

Several network/firwall vendors offer a feature that overrides the routing table to return traffic to the MAC address that initiated the connection. The idea here is to store the MAC address that the SYN packet came from in the connection table, then when sending return traffic for that flow, to send it to the MAC address that the SYN came from. This overrides the destination based routing table and helps prevent asymmetrical routing. Depending upon your point of view, this is either very helpful or very confusing.

This post simply catalogs the names various vendors call this feature. There is no standard name, as such it can be very confusing when talking with different vendors.