Distributed peer mentoring networks are a valuable and cost-effective way to support isolated faculty. Our National Science Foundation (NSF)-funded eAlliance project supports 12 such networks for women physics faculty at all ranks and across varied institutions. We discuss how they function for the participants, particularly the advantages of being outside local politics that lead to easier formation of trust, ability to request feedback about departmental concerns, and utility of sharing resources used at different institutions. We also describe the management of such networks and identify elements that help make them successful: confidentiality, external validation and voluntary commitment.