886

Port 886 is registered with IANA as iclcnet-locate with the description "ICL coNETion locate server," assignee Bob Lyon, and a blank reference field on both the TCP and UDP rows (verified against the live registry CSV). ICL stands for International Computers Limited, the dominant British mainframe maker formed in 1968 and known for the 2900 Series running the VME operating system; ICL was progressively absorbed by Fujitsu — 80 percent ownership by 1990, full ownership by 1998 — and rebranded Fujitsu Services in 2002. "coNETion" was an ICL enterprise networking product line, and the locate server on port 886 is a legacy directory or locator service from that environment. The IANA reference field is blank. There is no current standardized protocol or security profile associated with this port; it reflects a 1990s-era proprietary enterprise networking stack that has effectively disappeared from modern networks. Security-wise there is little specific to defend, but the port should never be expected on a current host. For an analyst, an open 886 is legacy and obscure — most likely a forgotten service on very old infrastructure or a misidentified port — and warrants identifying the actual listening process rather than trusting the registered name; nmap-services lists 886/tcp at roughly 0.000038, which is very low.

IANA assignment

iclcnet-locate — "ICL coNETion locate server"; reference (blank); assignee Bob Lyon; dual-registered 886/tcp + 886/udp [IANA-assigned, verified live] — IANA Service Name and Transport Protocol Port Number Registry

Range class

well-known (0–1023)

Prevalence

very rare; nmap-services 886/tcp ~0.000038 (de-facto) [Well-established] — nmap-services file

Related ports

887 (iclcnet_svinfo — companion ICL coNETion service)

Primary use

legacy ICL coNETion locator/directory service

Other/unofficial uses

none meaningful [Well-established]

Security implications

no current standardized service; an open 886 is legacy/obscure [Well-established]

Typically seen on

legacy ICL/Fujitsu enterprise environments (effectively none current)

Analyst note

An open 886 is legacy/obscure — identify the actual listening process rather than trusting the registered name.