- Patch VPN gateways quickly: they are a top initial access target.
- Use certificates or MFA rather than shared secrets.
- Investigate unexpected tunnels and proxies: they are also attacker tools.
Port 1994: cisco serial tunnel port
Port 1994 is assigned by IANA to stun-port (cisco serial tunnel port).
1994
How stun-port works
VPN, tunnels & proxiesTraffic is wrapped in a tunnel between the two ends, so the network in between only sees the tunnel.
- 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
- VPN, tunnels & proxies
Is port 1994 dangerous?
We have no specific security note for port 1994. Its risk depends on the program actually listening on it. General advice for vpn, tunnels & proxies services:
IANA registry entries for port 1994
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| stun-port | 1994 | TCP, UDP | cisco serial tunnel port | - | - |
// source: IANA service name and port number registry
Which program uses port 1994, and is it reachable?
Linux
sudo ss -ltnup 'sport = :1994' # process listening on 1994
sudo lsof -nP -i :1994macOS
sudo lsof -nP -i :1994
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 1994 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 1994 netstat -ano | findstr :1994
From another machine
nmap -p 1994 -sV <host> sudo nmap -sU -p 1994 <host> nc -zv <host> 1994
Block it in the firewall
sudo ufw deny 1994/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 1994" -Direction Inbound -LocalPort 1994 -Protocol TCP -Action Block # Windows
What is port 1994 used for?
Port 1994 is assigned by IANA to stun-port (cisco serial tunnel port).
Is port 1994 TCP or UDP?
Port 1994 is registered for TCP and UDP.
Is it safe to open port 1994?
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. Patch VPN gateways quickly: they are a top initial access target.
How do I check if port 1994 is open?
On Linux run "ss -ltnup 'sport = :1994'", on macOS "lsof -nP -i :1994", and on Windows "netstat -ano | findstr :1994" to see the local process. From another machine, "nmap -p 1994 <host>" shows whether it is reachable.