From The Free On-line Dictionary of Computing (19 January 2023):
Home Network Administration Protocol HNAP HNAP1
<protocol> (HNAP) A network protocol using SOAP over HTTP that lets manufacturers and administrtors to configure devices remotely. HNAP is typically used by ISPs to update Internet routers in customers' homes or workplaces.
Because it runs on many devices on the Internet, HNAP is a target for remote attacks or probes. These may start by attempting to fetch the URL "/HNAP1/" on the remote device.
(https://www.cisco.com/web/partners/downloads/guest/hnapprotocolwhitepaper.pdf)]
(https://isc.sans.edu/forums/diary/More+on+HNAP+What+is+it+How+to+Use+it+How+to+Find+it/17648/)]
(2018-08-09)