CyberHunter
Local dataset, no network
// Other services

Port 8999: Brodos Crypto Trade Protocol

Port 8999 is assigned by IANA to bctp (Brodos Crypto Trade Protocol).

8999

How bctp works

Other services
client:8999bctpresponse client:8999bctpresponse

The client sends a request to port 8999 and the bctp service answers.

Transport
TCP · UDP
Exposure risk
not rated depends on the program listening
Encryption
Unknownnot stated by the registry
IANA status
Assigned1 registered service
Range
Registered (1024-49151)
Category
Other services
01 Security

Is port 8999 dangerous?

We have no specific security note for port 8999. Its risk depends on the program actually listening on it. General advice for other services services:

  • Close the port if nothing on the host needs it.
  • Identify the process that listens on it (commands below) before opening it in a firewall.
  • Expose a service only to the networks that use it.
02 Registry

IANA registry entries for port 8999

ServicePortTransportDescriptionReferenceUpdated
bctp 8999 TCP, UDP Brodos Crypto Trade Protocol - 2002-02

// source: IANA service name and port number registry

03 Check it

Which program uses port 8999, and is it reachable?

Linux

sudo ss -ltnup 'sport = :8999'      # process listening on 8999
sudo lsof -nP -i :8999

macOS

sudo lsof -nP -i :8999

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 8999 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 8999
netstat -ano | findstr :8999

From another machine

nmap -p 8999 -sV <host>
sudo nmap -sU -p 8999 <host>
nc -zv <host> 8999

Block it in the firewall

sudo ufw deny 8999/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 8999" -Direction Inbound -LocalPort 8999 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 8999 used for?

Port 8999 is assigned by IANA to bctp (Brodos Crypto Trade Protocol).

Is port 8999 TCP or UDP?

Port 8999 is registered for TCP and UDP.

Is it safe to open port 8999?

It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Close the port if nothing on the host needs it.

How do I check if port 8999 is open?

On Linux run "ss -ltnup 'sport = :8999'", on macOS "lsof -nP -i :8999", and on Windows "netstat -ano | findstr :8999" to see the local process. From another machine, "nmap -p 8999 <host>" shows whether it is reachable.

05 Related
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