Port 121Encore Expedited Remote Pro.Call

Port 121 is assigned to Encore Expedited Remote Pro.Call, an obscure remote procedure-call service.

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

also known as erpc

Technical Details

what runs on :121

Encore Expedited Remote Pro.Call is registered on port :121 over tcp and udp to Jack ONeil. 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 rarely. What's listening is often not the registered service, so check before you assume.

find what's listening on :121

this machine

# linux
sudo ss -tulpn 'sport = :121'

# macos / bsd
sudo lsof -nP -i :121

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :121

another host

nmap -sV -p T:121 <host>
sudo nmap -sU -sV -p U:121 <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 :121

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 :121 yet

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

Record

iana registry entry

port: :121
service: Encore Expedited Remote Pro.Call
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: The IANA registry assigns TCP and UDP port 121 to Encore Expedited Remote Pro.Call (erpc), registered to Jack ONeil. Public deployment appears rare, with the service observed open in approximately 0.000675% of internet-wide scans.
lookups: 0rank 993
added: 2026-08-23
updated: 2026-08-23
references: IANA service name registry — port 121

Something wrong?

This record is maintained by the engineers who use port 121. 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 2026-08-23.

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 :121, by lookups.

port	service	proto	category	risk	views
:80	HTTP	TCPUDP	Web Services	caution	67.3k
:135	Microsoft EPMAP	TCPUDP	Security	caution	51.9k
:83	MIT ML Device	TCP	Network Services	caution	23.1k
:81	Torpark Onion Routing	TCP	Web Services	caution	21.4k
:143	IMAP	TCPUDP	Email	caution	20.7k
:109	POP2	TCP	Email	caution	17.9k
:135	DCE/RPC Endpoint Mapper	TCPUDP	Remote Access	caution	16.7k
:90	DNSIX	TCPUDP	Security	safe	16.1k

risk mix of the 8 listed

safe13%
caution88%

0 of 8 encrypted

Port :121Encore Expedited Remote Pro.Call

Technical Details

Security Information

Related Ports

Port 121Encore Expedited Remote Pro.Call