- 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 4901: FileLocator Remote Search Agent
Port 4901 is assigned by IANA to flr_agent (FileLocator Remote Search Agent), flr-agent (FileLocator Remote Search Agent IANA assigned this well-formed service name as a replacement for "flr_agent".).
4901
How flr_agent works
Other servicesThe client sends a request to port 4901 and the flr_agent service answers.
- Transport
- TCP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned2 registered services
- Range
- Registered (1024-49151)
- Category
- Other services
Is port 4901 dangerous?
We have no specific security note for port 4901. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 4901
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| flr_agent | 4901 | TCP | FileLocator Remote Search Agent | - | 2008-11-19 |
| flr-agent | 4901 | TCP | FileLocator Remote Search Agent IANA assigned this well-formed service name as a replacement for "flr_agent". | - | 2008-11-19 |
| - | 4901 | - | Reserved | - | - |
// source: IANA service name and port number registry
Which program uses port 4901, and is it reachable?
Linux
sudo ss -ltnup 'sport = :4901' # process listening on 4901
sudo lsof -nP -i :4901macOS
sudo lsof -nP -i :4901
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4901 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 4901 netstat -ano | findstr :4901
From another machine
nmap -p 4901 -sV <host> nc -zv <host> 4901
Block it in the firewall
sudo ufw deny 4901/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 4901" -Direction Inbound -LocalPort 4901 -Protocol TCP -Action Block # Windows
What is port 4901 used for?
Port 4901 is assigned by IANA to flr_agent (FileLocator Remote Search Agent), flr-agent (FileLocator Remote Search Agent IANA assigned this well-formed service name as a replacement for "flr_agent".).
Is port 4901 TCP or UDP?
Port 4901 is registered for TCP.
Is it safe to open port 4901?
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 4901 is open?
On Linux run "ss -ltnup 'sport = :4901'", on macOS "lsof -nP -i :4901", and on Windows "netstat -ano | findstr :4901" to see the local process. From another machine, "nmap -p 4901 <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