Port 105
csnet-ns and cso · TCP/UDP
| Range | System/well-known port (0–1023) |
|---|---|
| Protocol | TCP/UDP |
| Service | csnet-ns and cso |
Frequently asked questions
What is port 105 used for?
Port 105 is registered with the IANA for csnet-ns and cso (TCP/UDP). Description: CCSO name server protocol; Mailbox Name Nameserver.
Is port 105 a well-known port?
Yes. Port 105 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 105 is open?
Locally on Linux with ss -tulpn | grep ':105\b', on Windows with netstat -ano | findstr :105. To test a remote host use Test-NetConnection <host> -Port 105 in PowerShell or nc -zv <host> 105 on Linux/macOS.
How do I open port 105 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 105/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=105/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 105" -Direction Inbound -Protocol TCP -LocalPort 105 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | cso | CCSO name server protocol |
| UDP | cso | CCSO name server protocol |
| TCP | csnet-ns | Mailbox Name Nameserver |
| UDP | csnet-ns | Mailbox Name Nameserver |