- 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 4646: Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Protocol. The service name is used to construct the SRV service names "_dots-signal._udp" and "_dots-signal._tcp" for discovering DOTS servers used to establish DOTS signal channel.
Port 4646 is assigned by IANA to dots-signal (Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Protocol. The service name is used to construct the SRV service names "_dots-signal._udp" and "_dots-signal._tcp" for discovering DOTS servers used to establish DOTS signal channel.).
4646
How dots-signal works
Other servicesThe client sends a request to port 4646 and the dots-signal 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 4646 dangerous?
We have no specific security note for port 4646. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 4646
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| dots-signal | 4646 | TCP, UDP | Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Protocol. The service name is used to construct the SRV service names "_dots-signal._udp" and "_dots-signal._tcp" for discovering DOTS servers used to establish DOTS signal channel. | RFC 8973, RFC 9132 | 2021-06-14 |
// source: IANA service name and port number registry
Which program uses port 4646, and is it reachable?
Linux
sudo ss -ltnup 'sport = :4646' # process listening on 4646
sudo lsof -nP -i :4646macOS
sudo lsof -nP -i :4646
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4646 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 4646 netstat -ano | findstr :4646
From another machine
nmap -p 4646 -sV <host> sudo nmap -sU -p 4646 <host> nc -zv <host> 4646
Block it in the firewall
sudo ufw deny 4646/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 4646" -Direction Inbound -LocalPort 4646 -Protocol TCP -Action Block # Windows
What is port 4646 used for?
Port 4646 is assigned by IANA to dots-signal (Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Protocol. The service name is used to construct the SRV service names "_dots-signal._udp" and "_dots-signal._tcp" for discovering DOTS servers used to establish DOTS signal channel.).
Is port 4646 TCP or UDP?
Port 4646 is registered for TCP and UDP.
Is it safe to open port 4646?
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 4646 is open?
On Linux run "ss -ltnup 'sport = :4646'", on macOS "lsof -nP -i :4646", and on Windows "netstat -ano | findstr :4646" to see the local process. From another machine, "nmap -p 4646 <host>" shows whether it is reachable.
Other other services ports
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