Port 523IBM Db2

IBM Db2 administration and discovery traffic, distinct from the usual Db2 database listener on TCP 50000.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 7/10
lookups: 0

also known as DB2, IBM Db2 Administration Server

Technical Details

what runs on :523

IBM Db2 uses TCP 523 primarily for Administration Server control traffic, while UDP 523 can support Db2 discovery in deployments. The protocol is Db2-specific rather than HTTP, with version- and configuration-dependent negotiation and message framing; it is not the usual SQL listener, which commonly defaults to TCP 50000 (with environments sometimes assigning TCP 50001 for SSL). Encryption is not generally enabled by default for administration traffic.

Security Information

exposure of :523

risk score

7/ 10risk

treat as sensitive. widely scanned and regularly exploited when reachable — restrict it to known sources.

databases averages 3.8 across 74 ports — this one sits 3.2 above.

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

Do not expose Db2 administration or discovery services directly to the Internet. An exposed endpoint increases the attack surface for administrative authentication, information disclosure, and software vulnerabilities; restrict it to trusted management networks, apply IBM security fixes, and use network controls and encrypted management paths where supported.

Record

iana registry entry

port: :523
service: IBM Db2
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 7/10risk
category: Databases System
usage: TCP port 523 is historically used by the IBM Db2 Administration Server and related administration functions. Db2 deployments may also use UDP 523 for discovery or service advertisement; normal database client connections commonly use TCP 50000 instead.
lookups: 0rank 994
added: 2026-08-28
updated: 2026-08-28
references: IANA service name registry — port 523

Something wrong?

This record is maintained by the engineers who use port 523. 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 2026-08-28.

01edit any field on a page of its own
02a model checks it for accuracy and spam
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edit this record →back to the registry

Related Ports

all 74 in databases →

the 8 most looked-up other ports in databases — 74 ports carry that label.

port	service	proto	category	risk	views
:8882	Atlasz Secure App Server	TCP	Web Services	caution	66.9k
:9001	ETL Service Manager	TCPUDP	Databases	caution	28.6k
:2484	Oracle SSL Listener	TCPUDPtls	Security	caution	25.0k
:5495	Applix TM1 Admin	TCP	Databases	caution	24.8k
:591	FileMaker Web Sharing	TCP	Web Services	caution	23.1k
:1521	Oracle TNS Listener	TCP	Security	caution	19.6k
:21001	AMLFilter Admin	TCP	Security	caution	19.2k
:18206	Audition FAM DB	TCPUDP	Databases	caution	19.1k

risk mix of the 8 listed

caution100%

1 of 8 encrypted

Port :523IBM Db2

Technical Details

Security Information

Related Ports

Port 523IBM Db2