- 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 3568: DOF Secure Tunnel
Port 3568 is assigned by IANA to dof-tunnel-sec (DOF Secure Tunnel).
3568
How dof-tunnel-sec 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 3568 dangerous?
We have no specific security note for port 3568. Its risk depends on the program actually listening on it. General advice for vpn, tunnels & proxies services:
IANA registry entries for port 3568
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| dof-tunnel-sec | 3568 | TCP, UDP | DOF Secure Tunnel | - | 2015-04-23 |
// source: IANA service name and port number registry
Which program uses port 3568, and is it reachable?
Linux
sudo ss -ltnup 'sport = :3568' # process listening on 3568
sudo lsof -nP -i :3568macOS
sudo lsof -nP -i :3568
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 3568 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 3568 netstat -ano | findstr :3568
From another machine
nmap -p 3568 -sV <host> sudo nmap -sU -p 3568 <host> nc -zv <host> 3568
Block it in the firewall
sudo ufw deny 3568/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 3568" -Direction Inbound -LocalPort 3568 -Protocol TCP -Action Block # Windows
What is port 3568 used for?
Port 3568 is assigned by IANA to dof-tunnel-sec (DOF Secure Tunnel).
Is port 3568 TCP or UDP?
Port 3568 is registered for TCP and UDP.
Is it safe to open port 3568?
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 3568 is open?
On Linux run "ss -ltnup 'sport = :3568'", on macOS "lsof -nP -i :3568", and on Windows "netstat -ano | findstr :3568" to see the local process. From another machine, "nmap -p 3568 <host>" shows whether it is reachable.