660

Port 660/tcp is registered with IANA as mac-srvr-admin with the description "MacOS Server Admin," assignee and contact Forest Hill, and a blank reference field (dual-registered on TCP and UDP). It denotes legacy Apple Mac OS X Server and AppleShare IP remote administration — the channel used for remote management of one or more servers, including installing and configuring Mac OS X Server, managing file share points, and configuring service settings via Apple's server admin utilities (Cisco's NBAR2 classifies it under network-management). The IANA reference field is blank. Security-wise the modern footprint is minimal, as the legacy admin tooling has largely been superseded; an open 660 indicates an old Mac OS X Server. For an analyst, an open 660 is a legacy Mac OS X Server admin endpoint and is rare today.

IANA assignment

mac-srvr-admin — "MacOS Server Admin"; reference (blank — no RFC cited in IANA registry); assignee Forest Hill; dual-registered 660/tcp + 660/udp [IANA-assigned] — IANA Service Name and Transport Protocol Port Number Registry

Range class

well-known (0–1023)

Prevalence

very low; nmap-services de-facto low [Well-established] — nmap-services file

Related ports

548 (AFP), AppleShare

Primary use

legacy Apple Mac OS X Server / AppleShare IP remote administration

Other/unofficial uses

none today [Well-established]

Security implications

minimal footprint; legacy admin tooling largely superseded [Well-established]

Typically seen on

legacy Mac OS X Servers

Analyst note

An open 660 is a legacy Mac OS X Server admin endpoint; rare today.