Port 9876Session Director

Session Director traffic assigned to TCP port 9876.

transport: tcp
in transit: cleartext
assignment: official
risk: 1/10
lookups: 0

also known as sd

Technical Details

what runs on :9876

Session Director is registered on port :9876 over tcp to Van Jacobson. We don't have a technical write-up for it beyond the IANA registry entry.

In nmap's internet-wide scan data this port is found open sometimes. What's listening is often not the registered service, so check before you assume.

find what's listening on :9876

this machine

# linux
sudo ss -tlpn 'sport = :9876'

# macos / bsd
sudo lsof -nP -i :9876

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :9876

another host

nmap -sV -p T:9876 <host>

run it? the handshake, the implementations you meet in the wild and the flags that matter come from the engineers who do.

add technical details

Security Information

exposure of :9876

risk score

1/ 10safe

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

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

every listening transport is another surface to filter at the edge

security overview

no security notes recorded for :9876 yet

known exploits, hardening advice, what a compromise looks like — suggest an edit if you know its exposure.

Record

iana registry entry

port: :9876
service: Session Director
transport: TCP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: TCP/9876 is assigned as “Session Director” in the IANA registry. The assignment is registered to Van Jacobson, but public protocol and deployment details are not established here.
lookups: 0rank 993
added: 2026-08-20
updated: 2026-08-20
references: IANA service name registry — port 9876

Something wrong?

This record is maintained by the engineers who use port 9876. 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 2026-08-20.

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

browse categories →

ports registered around :9876, by lookups.

port	service	proto	category	risk	views
:9898	Tripwire FIM	TCP	Security	caution	15.0k
:9898	MonkeyCom	TCPUDP	Network Services	caution	13.6k
:9875	Club Penguin	TCP	Gaming	caution	7.3k
:9900	ISDN Q.921 User Adaptation (IUA)	TCPUDPSCTP	Network Services	caution	0
:9877	X.510 Wrapper Protocol	TCP	—	safe	0
:9875	Session Announcement Protocol v1	TCPUDP	Streaming	safe	0
:9909	domaintime	TCPUDP	—	safe	0
:9911	SYPECom Transport Protocol	TCPUDP	Network Services	safe	0

risk mix of the 8 listed

safe50%
caution50%

0 of 8 encrypted

Port :9876Session Director

Technical Details

Security Information

Related Ports

Port 9876Session Director