Optimizing wide area network (WAN) traffic by providing home site deduplication information to a cache site

Methods, systems, and physical computer-readable storage medium are provided to optimize WAN traffic on cloud networking sites. In an embodiment, by way of example only, a method includes fetching deduplication information from a home site to build a repository comprising duplicate peer file sets, one or more of the duplicate peer file sets including one or more peer files, referring to the repository to determine whether a target file corresponds with a cache copy of a peer file of the one or more peer files included in the duplicate peer file sets, and creating a local copy of the peer file of the one or more peer files, if a determination is made that the target file corresponds with the cache copy of the peer file of the one or more peer files included in the duplicate peer file sets.