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// Other services

Port 2203: b2 Runtime Protocol

Port 2203 is assigned by IANA to b2-runtime (b2 Runtime Protocol).

2203

How b2-runtime works

Other services
client:2203b2-runtimeresponse client:2203b2-runtimeresponse

The client sends a request to port 2203 and the b2-runtime 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 2203 dangerous?

We have no specific security note for port 2203. 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 2203

ServicePortTransportDescriptionReferenceUpdated
b2-runtime 2203 TCP, UDP b2 Runtime Protocol - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 2203, and is it reachable?

Linux

sudo ss -ltnup 'sport = :2203'      # process listening on 2203
sudo lsof -nP -i :2203

macOS

sudo lsof -nP -i :2203

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 2203 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 2203
netstat -ano | findstr :2203

From another machine

nmap -p 2203 -sV <host>
sudo nmap -sU -p 2203 <host>
nc -zv <host> 2203

Block it in the firewall

sudo ufw deny 2203/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 2203" -Direction Inbound -LocalPort 2203 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 2203 used for?

Port 2203 is assigned by IANA to b2-runtime (b2 Runtime Protocol).

Is port 2203 TCP or UDP?

Port 2203 is registered for TCP and UDP.

Is it safe to open port 2203?

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 2203 is open?

On Linux run "ss -ltnup 'sport = :2203'", on macOS "lsof -nP -i :2203", and on Windows "netstat -ano | findstr :2203" to see the local process. From another machine, "nmap -p 2203 <host>" shows whether it is reachable.

05 Related
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