Port 2564HP 3000 NS/VT block-mode Telnet

HP 3000 NS/VT block-mode terminal access using Telnet on TCP or UDP port 2564.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 6/10
lookups: 0

also known as hp-3000-telnet, NS/VT Telnet

Technical Details

what runs on :2564

Port 2564 is assigned for HP 3000 NS/VT block-mode Telnet over both TCP and UDP. NS/VT is a Hewlett-Packard terminal protocol for HP 3000 systems; its block-mode operation supports terminal applications that exchange screen-oriented input and output rather than ordinary character-at-a-time Telnet interaction. Deployments are uncommon and are primarily associated with legacy MPE/iX hosts; this service should not be confused with the conventional Telnet service on TCP port 23.

Security Information

exposure of :2564

risk score

6/ 10risk

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

remote access averages 3.8 across 207 ports — this one sits 2.2 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

NS/VT is a legacy remote-terminal service and should not normally be exposed to the public Internet. Telnet-style sessions generally provide no encryption, so credentials and terminal data may be captured; restrict access to trusted management networks or protect it with an appropriate secure tunnel.

Record

iana registry entry

port: :2564
service: HP 3000 NS/VT block-mode Telnet
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 6/10risk
category: Remote Access System
usage: This port provides NS/VT block-mode terminal access to HP 3000 systems running MPE/iX. Engineers may encounter it on legacy HP 3000 hosts supporting block-oriented terminal applications and forms.
lookups: 0rank 993
added: 2026-09-15
updated: 2026-09-22
references: IANA service name registry — port 2564

Something wrong?

This record is maintained by the engineers who use port 2564. 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 2026-09-22.

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edit this record →back to the registry

Related Ports

all 207 in remote access →

the 8 most looked-up other ports in remote access — 207 ports carry that label.

port	service	proto	category	risk	views
:8000	Intel Remote Desktop / Alternate HTTP Port	TCP	Web Services	safe	84.3k
:8888	D2GS Admin Console	TCP	Remote Access	caution	83.7k
:8881	Atlasz Secure Server	TCP	Web Services	caution	67.6k
:5938	TeamViewer	TCPUDP	Remote Access	caution	65.0k
:8291	Winbox MikroTik Admin	TCP	Security	caution	62.9k
:8008	IBM HTTP Server Admin	TCP	Web Services	caution	58.3k
:135	Microsoft EPMAP	TCPUDP	Security	caution	51.9k
:23	Telnet	TCP	Remote Access	caution	34.8k

risk mix of the 8 listed

safe13%
caution88%

0 of 8 encrypted

Port :2564HP 3000 NS/VT block-mode Telnet

Technical Details

Security Information

Related Ports

Port 2564HP 3000 NS/VT block-mode Telnet