Examples disclosed herein relate to identification of an alternate principal member port by a target device in a Storage Area Network (SAN). In some examples, a target device in a SAN may determine that a principal member port of a target driven peer zone on the target device is likely to fail based on diagnostic information related to the principal member port. The target driven peer zone may be configured in the SAN via the target device. In response to determining, the target device may identify an alternate principal member port on the target device. The target device may perform an action to indicate the alternate principal member port as the principal member port.