Port 1611Interlibrary Loan

Interlibrary Loan (ILL) service traffic assigned to TCP and UDP port 1611.

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

also known as ill

Technical Details

what runs on :1611

Interlibrary Loan is registered on port :1611 over tcp and udp to Niall Murphy. 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 never observed open, so if it's open on your network it's more likely a custom or misconfigured service than the registered one.

find what's listening on :1611

this machine

# linux
sudo ss -tulpn 'sport = :1611'

# macos / bsd
sudo lsof -nP -i :1611

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :1611

another host

nmap -sV -p T:1611 <host>
sudo nmap -sU -sV -p U:1611 <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 :1611

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 · udp

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

security overview

no security notes recorded for :1611 yet

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

Record

iana registry entry

port: :1611
service: Interlibrary Loan
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: IANA assigns TCP and UDP port 1611 to Inter Library Loan services. The assignment is registered to Niall Murphy, with no recorded registration date or additional notes.
lookups: 0rank 993
added: 2026-09-17
updated: 2026-09-17
references: IANA service name registry — port 1611

Something wrong?

This record is maintained by the engineers who use port 1611. 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 2026-09-17.

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 :1611, by lookups.

port	service	proto	category	risk	views
:1645	RADIUS Authentication (Cisco/Juniper)	TCPUDP	Security	caution	15.1k
:1646	RADIUS Accounting	TCPUDP	Security	caution	13.1k
:1581	MIL-STD-2045-47001 VMF	UDP	Security	caution	10.6k
:1550	Gadu-Gadu C2C		Network Services	caution	7.7k
:1589	Cisco VQP / VMPS	UDP	Security	caution	6.2k
:1627	iSketch		Gaming	caution	4.5k
:1666	Perforce	TCP	File Transfer	caution	4.4k
:1547	Laplink	TCPUDP	File Transfer	caution	4.1k

risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :1611Interlibrary Loan

Technical Details

Security Information

Related Ports

Port 1611Interlibrary Loan