Port 10809Network Block Device (NBD)

NBD exposes a remote block device over TCP, commonly on port 10809, for Linux systems and virtual machines.

transport: tcp
in transit: cleartext
assignment: official
risk: 8/10
lookups: 0

also known as nbd, nbd-server

Technical Details

what runs on :10809

NBD runs over TCP, conventionally on port 10809, with no UDP counterpart. In the new-style protocol, the server begins with a fixed handshake and the client negotiates an export and features; the connection then carries framed block requests and replies, including operations such as reads, writes, and flushes. Linux nbd-server and QEMU are common implementations. NBD itself does not encrypt traffic by default, though protocol versions with STARTTLS support can negotiate TLS.

Security Information

exposure of :10809

risk score

8/ 10risk

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

system averages 2.7 across 1,001 ports — this one sits 5.3 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

every listening transport is another surface to filter at the edge

security overview

An exposed NBD export can give a remote client direct access to block data, potentially including the ability to modify it; the base protocol does not provide authentication. Do not expose it to the public internet: restrict access with firewall rules or a private network, and use TLS and appropriate access controls where supported.

Record

iana registry entry

port: :10809
service: Network Block Device (NBD)
transport: TCP
encryption: cleartext
assignment: iana registered
risk: 8/10risk
category: System Virtualization
usage: Linux NBD servers and QEMU can listen here to export a block device that a client attaches as local storage. The registered service matches this established use; 10809 is NBD’s conventional TCP port.
lookups: 0rank 993
added: 2026-10-16
updated: 2026-10-16
references: IANA service name registry — port 10809

Something wrong?

This record is maintained by the engineers who use port 10809. 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 2026-10-16.

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

all 1,001 in system →

the 8 most looked-up other ports in system — 1,001 ports carry that label.

port	service	proto	category	risk	views
:8888	Sun Answerbook & Alt HTTP	TCP	Web Services	caution	123.9k
:4664	Google Desktop Search	TCP	System	caution	67.2k
:8008	IBM HTTP Server Admin	TCP	Web Services	caution	58.3k
:3268	Microsoft Global Catalog (GC)	TCPUDP	Security	caution	54.6k
:135	Microsoft EPMAP	TCPUDP	Security	caution	51.9k
:9080	WebSphere HTTP Transport (default)	TCP	Web Services	caution	51.6k
:23	Telnet	TCP	Remote Access	caution	34.8k
:12489	NSClient Monitoring Agent	TCP	Network Services	caution	30.0k

risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :10809Network Block Device (NBD)

Technical Details

Security Information

Related Ports

Port 10809Network Block Device (NBD)