Port 63WHOIS++

Historic WHOIS++ directory lookup service assigned to TCP and UDP port 63.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 2/10
lookups: 0

also known as whoispp, WHOIS Plus Plus

Technical Details

what runs on :63

WHOIS++ is a text-based directory query protocol associated with TCP port 63; IANA also lists UDP. A client sends textual commands and search criteria to a server, which returns directory records and may use distributed indexes, centroids, or referrals to locate information across other servers. Implementations normally use cleartext request/response exchanges rather than an encrypted transport, and the service has been superseded in practice by newer directory and registry systems. The IANA entry is historic and aliases the whoispp service name, so contemporary service-discovery tools may not recognize it.

Security Information

exposure of :63

risk score

2/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

network services averages 2.6 across 1,594 ports — this one sits 0.6 below.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp · udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

WHOIS++ should not normally be exposed to the public Internet because it is obsolete, cleartext, and may disclose directory records or server topology. Internet-wide scanning is unlikely to find it, but an exposed legacy implementation should be restricted to trusted networks and checked for outdated software and unintended information disclosure.

Record

iana registry entry

port: :63
service: WHOIS++
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 2/10safe
category: Network Services
usage: WHOIS++ is a legacy, distributed directory service and an extension of the original WHOIS model. Engineers may encounter port 63 on old directory servers or archival systems, but it is not commonly deployed on the modern Internet.
lookups: 0rank 993
added: 2026-09-16
updated: 2026-09-22
references: IANA service name registry — port 63

Something wrong?

This record is maintained by the engineers who use port 63. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-09-22.

01edit any field on a page of its own
02a model checks it for accuracy and spam
03clean and confident goes live immediately

edit this record →back to the registry

Related Ports

all 1,594 in network services →

the 8 most looked-up other ports in network services — 1,594 ports carry that label.

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:3268	Microsoft Global Catalog (GC)	TCPUDP	Security	caution	54.6k
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:3128	Tatsoft Default HTTP Proxy	TCP	Web Services	caution	46.8k

risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :63WHOIS++

Technical Details

Security Information

Related Ports

Port 63WHOIS++