Port 4786Cisco Smart Install

Cisco Smart Install uses TCP 4786 to provision and manage network switches; exposed instances can be vulnerable to unauthenticated attacks.

inNetwork Services System

transport: tcp
in transit: cleartext
assignment: official
risk: 9/10
lookups: 0

also known as TCP/4786

Technical Details

what runs on :4786

TCP 4786 carries Cisco Smart Install's proprietary, binary-framed protocol. A switch acting as a Smart Install client communicates with a director to obtain provisioning information, such as configuration or software images; transfers may also involve TFTP. The protocol is not encrypted by default, and this port is distinct from the more familiar management interfaces such as SSH or HTTPS.

Security Information

exposure of :4786

risk score

9/ 10critical

assume it is being scanned right now. do not expose this port to untrusted networks; put a vpn or bastion in front of it.

network services averages 2.6 across 1,584 ports — this one sits 6.4 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

Do not expose TCP 4786 to the public internet. Smart Install has had serious vulnerabilities, including CVE-2018-0171, which can allow unauthenticated remote code execution on affected Cisco devices when the feature is enabled. Disable Smart Install if unused, apply vendor fixes, and restrict access to trusted management networks.

Record

iana registry entry

port: :4786
service: Cisco Smart Install
transport: TCP
encryption: cleartext
assignment: iana registered
risk: 9/10critical
category: Network Services System
usage: Cisco Smart Install uses this port for communication between a network switch acting as a director and switches being provisioned. Engineers may encounter it on Cisco network equipment, though the IANA assignment is rarely seen open in internet-wide scans.
lookups: 0rank 993
added: 2026-10-06
updated: 2026-10-06
references: IANA service name registry — port 4786

Something wrong?

This record is maintained by the engineers who use port 4786. 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 2026-10-06.

01edit any field on a page of its own
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edit this record →back to the registry

Related Ports

all 1,584 in network services →

the 8 most looked-up other ports in network services — 1,584 ports carry that label.

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:9080	Groove RPC	TCPUDP	Web Services	caution	70.8k
:6543	Jetnet	UDP	Network Services	caution	65.3k
:5938	TeamViewer	TCPUDP	Remote Access	caution	65.0k
:8291	Winbox MikroTik Admin	TCP	Security	caution	62.9k
:3233	WhiskerControl Protocol	TCPUDP	Network Services	caution	61.9k
:3268	Microsoft Global Catalog (GC)	TCPUDP	Security	caution	54.6k
:135	Microsoft EPMAP	TCPUDP	Security	caution	51.9k
:3128	Tatsoft Default HTTP Proxy	TCP	Web Services	caution	46.8k

risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :4786Cisco Smart Install

Technical Details

Security Information

Related Ports

Port 4786Cisco Smart Install