- 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 105: Mailbox Name Nameserver
Port 105 is assigned by IANA to csnet-ns (Mailbox Name Nameserver), cso (CCSO name server protocol).
105
How csnet-ns works
Other servicesThe client sends a request to port 105 and the csnet-ns service answers.
- Transport
- TCP · UDP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned2 registered services
- Range
- Well-known (0-1023)
- Category
- Other services
Is port 105 dangerous?
We have no specific security note for port 105. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 105
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| csnet-ns | 105 | TCP, UDP | Mailbox Name Nameserver | - | - |
| cso | 105 | TCP, UDP | CCSO name server protocol | - | - |
// source: IANA service name and port number registry
Which program uses port 105, and is it reachable?
Linux
sudo ss -ltnup 'sport = :105' # process listening on 105
sudo lsof -nP -i :105macOS
sudo lsof -nP -i :105
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 105 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 105 netstat -ano | findstr :105
From another machine
nmap -p 105 -sV <host> sudo nmap -sU -p 105 <host> nc -zv <host> 105
Block it in the firewall
sudo ufw deny 105/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 105" -Direction Inbound -LocalPort 105 -Protocol TCP -Action Block # Windows
What is port 105 used for?
Port 105 is assigned by IANA to csnet-ns (Mailbox Name Nameserver), cso (CCSO name server protocol).
Is port 105 TCP or UDP?
Port 105 is registered for TCP and UDP.
Is it safe to open port 105?
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 105 is open?
On Linux run "ss -ltnup 'sport = :105'", on macOS "lsof -nP -i :105", and on Windows "netstat -ano | findstr :105" to see the local process. From another machine, "nmap -p 105 <host>" shows whether it is reachable.
Other other services ports
:4444 Metasploit default / krb524 tcp · udp · high risk :31337 Back Orifice / elite tcp · udp · high risk :1 TCP Port Service Multiplexer tcp · udp :5 Remote Job Entry tcp · udp :9 Discard tcp · udp · sctp · dccp :11 Active Users tcp · udp :17 Quote of the Day tcp · udp :18 Message Send Protocol (historic) tcp · udp