- 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.
Port 3390: Distributed Service Coordinator
Port 3390 is assigned by IANA to dsc (Distributed Service Coordinator).
3390
How dsc works
Other servicesThe client sends a request to port 3390 and the dsc 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
Is port 3390 dangerous?
We have no specific security note for port 3390. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 3390
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| dsc | 3390 | TCP, UDP | Distributed Service Coordinator | - | - |
// source: IANA service name and port number registry
Which program uses port 3390, and is it reachable?
Linux
sudo ss -ltnup 'sport = :3390' # process listening on 3390
sudo lsof -nP -i :3390macOS
sudo lsof -nP -i :3390
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3390 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 3390 netstat -ano | findstr :3390
From another machine
nmap -p 3390 -sV <host> sudo nmap -sU -p 3390 <host> nc -zv <host> 3390
Block it in the firewall
sudo ufw deny 3390/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 3390" -Direction Inbound -LocalPort 3390 -Protocol TCP -Action Block # Windows
What is port 3390 used for?
Port 3390 is assigned by IANA to dsc (Distributed Service Coordinator).
Is port 3390 TCP or UDP?
Port 3390 is registered for TCP and UDP.
Is it safe to open port 3390?
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 3390 is open?
On Linux run "ss -ltnup 'sport = :3390'", on macOS "lsof -nP -i :3390", and on Windows "netstat -ano | findstr :3390" to see the local process. From another machine, "nmap -p 3390 <host>" shows whether it is reachable.
Other other services ports
:4444 Metasploit default / krb524 tcp · udp · high risk :31337 Back Orifice / elite tcp · udp · high risk :1 TCP Port Service Multiplexer tcp · udp :5 Remote Job Entry tcp · udp :9 Discard tcp · udp · sctp · dccp :11 Active Users tcp · udp :17 Quote of the Day tcp · udp :18 Message Send Protocol (historic) tcp · udp