Port 2604Quagga/FRRouting OSPF daemon VTY

TCP/2604 is commonly the Quagga/FRRouting OSPF daemon’s management CLI, not OSPF routing traffic.

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

also known as nsc-ccs, Quagga ospfd

Technical Details

what runs on :2604

The IANA assignment is nsc-ccs, but a well-established real-world use of TCP/2604 is the Quagga/FRRouting ospfd VTY: a line-oriented management CLI, not the OSPF protocol itself. OSPF routing messages use IP protocol 89, not TCP or UDP. The VTY accepts a TCP connection and provides command-line access according to the daemon’s configured authentication and privilege settings; it is commonly kept on a management interface or bound to localhost. Neighboring Quagga/FRR VTY ports include 2601 for zebra, 2602 for ripd, and 2605 for bgpd. The VTY convention applies to TCP; UDP/2604 is not the normal ospfd management listener.

Security Information

exposure of :2604

risk score

8/ 10risk

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

remote access averages 3.7 across 190 ports — this one sits 4.3 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 · udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

An exposed VTY is a router-management surface: an attacker who can authenticate may inspect or alter routing configuration and affect network traffic. Keep it off the public internet and limit access with management-plane ACLs, a VPN, or an out-of-band network. The CLI is not encrypted by default, so credentials and commands may be exposed to observers on the path.

Record

iana registry entry

port: :2604
service: Quagga/FRRouting OSPF daemon VTY
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 8/10risk
category: Remote Access Network Services
usage: Although IANA lists the service as nsc-ccs, TCP port 2604 is conventionally used by Quagga and FRRouting for the ospfd VTY management interface. It is generally encountered on routers and lab systems, and is usually restricted to local or trusted management access; internet-wide scan data has not observed it open.
lookups: 0rank 993
added: 2026-09-23
updated: 2026-09-23
references: IANA service name registry — port 2604

Something wrong?

This record is maintained by the engineers who use port 2604. 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 2026-09-23.

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Related Ports

all 190 in remote access →

the 8 most looked-up other ports in remote access — 190 ports carry that label.

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:8888	D2GS Admin Console	TCP	Remote Access	caution	83.7k
:8881	Atlasz Secure Server	TCP	Web Services	caution	67.6k
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: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 :2604Quagga/FRRouting OSPF daemon VTY

Technical Details

Security Information

Related Ports

Port 2604Quagga/FRRouting OSPF daemon VTY