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// Other services

Port 1837: csoft1

Port 1837 is assigned by IANA to csoft1 (csoft1).

1837

How csoft1 works

Other services
client:1837csoft1response client:1837csoft1response

The client sends a request to port 1837 and the csoft1 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 1837 dangerous?

We have no specific security note for port 1837. 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 1837

ServicePortTransportDescriptionReferenceUpdated
csoft1 1837 TCP, UDP csoft1 - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 1837, and is it reachable?

Linux

sudo ss -ltnup 'sport = :1837'      # process listening on 1837
sudo lsof -nP -i :1837

macOS

sudo lsof -nP -i :1837

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 1837 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 1837
netstat -ano | findstr :1837

From another machine

nmap -p 1837 -sV <host>
sudo nmap -sU -p 1837 <host>
nc -zv <host> 1837

Block it in the firewall

sudo ufw deny 1837/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 1837" -Direction Inbound -LocalPort 1837 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 1837 used for?

Port 1837 is assigned by IANA to csoft1 (csoft1).

Is port 1837 TCP or UDP?

Port 1837 is registered for TCP and UDP.

Is it safe to open port 1837?

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 1837 is open?

On Linux run "ss -ltnup 'sport = :1837'", on macOS "lsof -nP -i :1837", and on Windows "netstat -ano | findstr :1837" to see the local process. From another machine, "nmap -p 1837 <host>" shows whether it is reachable.

05 Related
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