Port 3661IBM Tivoli Directory Service over SSL

Port 3661 is assigned to IBM Tivoli Directory Service over SSL, an uncommon LDAP directory endpoint not typically seen in internet scans.

inSecurity Network Services

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

also known as can-ferret-ssl, IBM Tivoli Directory Server, LDAPS

Technical Details

what runs on :3661

The IANA assignment describes IBM Tivoli Directory Service using SSL. In a normal TCP deployment, the client establishes an SSL/TLS connection first, then exchanges LDAP messages inside that encrypted stream. IANA lists both TCP and UDP, but SSL-protected LDAP is normally a TCP service; a UDP listener should not be assumed to provide the same functionality. Port 3661 is not the conventional LDAPS port (636).

Security Information

exposure of :3661

risk score

2/ 10safe

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

security averages 3.1 across 358 ports — this one sits 1.1 below.

in transit

encrypted

payloads are protected on the wire

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

Encryption protects the connection in transit, but does not by itself prevent directory enumeration, password guessing, or access to sensitive directory data when authentication or access controls are weak. Keep directory services off the public internet unless there is a specific need and strong access restrictions; no port-specific vulnerability is implied by the assignment.

Record

iana registry entry

port: :3661
service: IBM Tivoli Directory Service over SSL
transport: TCPUDP
encryption: tls / encrypted
assignment: iana registered
risk: 2/10safe
category: Security Network Services
usage: A listener would be an IBM Tivoli directory service configured to accept encrypted LDAP connections on port 3661. This is uncommon in internet scans; standard LDAP and LDAPS commonly use ports 389 and 636, respectively.
lookups: 0rank 993
added: 2026-10-01
updated: 2026-10-01
references: IANA service name registry — port 3661

Something wrong?

This record is maintained by the engineers who use port 3661. 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 2026-10-01.

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risk mix of the 8 listed

caution100%

2 of 8 encrypted

Port :3661IBM Tivoli Directory Service over SSL

Technical Details

Security Information

Related Ports

Port 3661IBM Tivoli Directory Service over SSL