- 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 28001: PQ Service
Port 28001 is assigned by IANA to pqsp (PQ Service).
28001
How pqsp works
Other servicesThe client sends a request to port 28001 and the pqsp service answers.
- Transport
- TCP
- 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 28001 dangerous?
We have no specific security note for port 28001. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 28001
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| pqsp | 28001 | TCP | PQ Service | - | 2009-09-15 |
| - | 28001 | - | Reserved | - | - |
// source: IANA service name and port number registry
Which program uses port 28001, and is it reachable?
Linux
sudo ss -ltnup 'sport = :28001' # process listening on 28001
sudo lsof -nP -i :28001macOS
sudo lsof -nP -i :28001
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 28001 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 28001 netstat -ano | findstr :28001
From another machine
nmap -p 28001 -sV <host> nc -zv <host> 28001
Block it in the firewall
sudo ufw deny 28001/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 28001" -Direction Inbound -LocalPort 28001 -Protocol TCP -Action Block # Windows
What is port 28001 used for?
Port 28001 is assigned by IANA to pqsp (PQ Service).
Is port 28001 TCP or UDP?
Port 28001 is registered for TCP.
Is it safe to open port 28001?
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 28001 is open?
On Linux run "ss -ltnup 'sport = :28001'", on macOS "lsof -nP -i :28001", and on Windows "netstat -ano | findstr :28001" to see the local process. From another machine, "nmap -p 28001 <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