1. A method of routing directory service operations in a directory service network that supports a hierarchical structure of directory entries, wherein the directory service network comprises a plurality of directory servers, the method comprising: receiving, at a router, a directory service operation relating to a directory entry; determining that one of the plurality of directory servers has been disconnected or is unavailable; marking the one of the plurality of directory servers as disconnected or unavailable in the directory server knowledge list, the marking comprising marking a time associated with the determination of the one of the plurality of directory servers as disconnected or unavailable; determining, at a processor, which one or more of the plurality of directory servers are able to process the directory service operation by more than merely transmitting or receiving the directory service operation, wherein the determination is made using, at least in part, a directory server knowledge list, the directory server knowledge list comprising a type of information served by each of the plurality of directory servers; selecting, at the processor, one of the plurality of directory servers based at least in part on the determination of ability to process the directory service operation; and routing, by the router, the directory service operation to the selected directory server.