Port 91

mit-dov · TCP/UDP

RangeSystem/well-known port (0–1023)
ProtocolTCP/UDP
Servicemit-dov

Frequently asked questions

What is port 91 used for?

Port 91 is registered with the IANA for mit-dov (TCP/UDP). Description: MIT Dover Spooler.

Is port 91 a well-known port?

Yes. Port 91 is in the range 0–1023 (system or well-known ports). On Linux and macOS only privileged processes may bind to these ports.

How do I check whether port 91 is open?

Locally on Linux with ss -tulpn | grep ':91\b', on Windows with netstat -ano | findstr :91. To test a remote host use Test-NetConnection <host> -Port 91 in PowerShell or nc -zv <host> 91 on Linux/macOS.

How do I open port 91 in the firewall?

Ubuntu/Debian (ufw): sudo ufw allow 91/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=91/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 91" -Direction Inbound -Protocol TCP -LocalPort 91 -Action Allow.

IANA registry entries

ProtocolServiceDescription (IANA)
TCPmit-dovMIT Dover Spooler
UDPmit-dovMIT Dover Spooler

Nearby entries