Port 5251CA eTrust VM Service

TCP/UDP 5251 is assigned to the CA eTrust VM Service, a little-documented service registered to Kevin Bond.

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

also known as caevms

Technical Details

what runs on :5251

CA eTrust VM Service is registered on port :5251 over tcp and udp to Kevin Bond, assigned November 2004. 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 :5251

this machine

# linux
sudo ss -tulpn 'sport = :5251'

# macos / bsd
sudo lsof -nP -i :5251

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :5251

another host

nmap -sV -p T:5251 <host>
sudo nmap -sU -sV -p U:5251 <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 :5251

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 :5251 yet

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

Record

iana registry entry

port: :5251
service: CA eTrust VM Service
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: CA eTrust VM Service is the IANA assignment for TCP and UDP port 5251, registered to Kevin Bond in 2004. There is no well-established public information about its implementation or common deployment.
lookups: 0rank 993
added: 2026-10-07
updated: 2026-10-07
references: IANA service name registry — port 5251

Something wrong?

This record is maintained by the engineers who use port 5251. 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 2026-10-07.

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 :5251, by lookups.

port	service	proto	category	risk	views
:5247	CAPWAP Data	UDP	Network Services	caution	17.9k
:5223	XMPP over SSL	TCPtls	Security	caution	16.3k
:5246	CAPWAP Control	UDP	Network Services	caution	13.2k
:5269	XMPP Server Connection	TCP	Network Services	caution	12.8k
:5222	XMPP Client Connection	TCP	Network Services	caution	11.7k
:5298	XMPP Link-Local / Serverless Messaging	TCPUDP	Network Services	caution	9.5k
:5190	ICQ & AIM	TCP	Voice and Chat	caution	8.5k
:5314	Ginever.net Port	TCPUDP	Network Services	caution	7.4k

risk mix of the 8 listed

caution100%

1 of 8 encrypted

Port :5251CA eTrust VM Service

Technical Details

Security Information

Related Ports

Port 5251CA eTrust VM Service