Port 4500
ipsec-nat-t · TCP/UDP
| Range | Registered port (1024–49151) |
|---|---|
| Protocol | TCP/UDP |
| Service | ipsec-nat-t |
| Reference | RFC 9329, RFC 3948, RFC 7296 |
| Modified | 2022-09-15 |
Frequently asked questions
What is port 4500 used for?
Port 4500 is registered with the IANA for ipsec-nat-t (TCP/UDP). Description: IPsec NAT-Traversal.
Is port 4500 a well-known port?
No. Port 4500 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.
How do I check whether port 4500 is open?
Locally on Linux with ss -tulpn | grep ':4500\b', on Windows with netstat -ano | findstr :4500. To test a remote host use Test-NetConnection <host> -Port 4500 in PowerShell or nc -zv <host> 4500 on Linux/macOS.
How do I open port 4500 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 4500/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=4500/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 4500" -Direction Inbound -Protocol TCP -LocalPort 4500 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | ipsec-nat-t | IPsec NAT-Traversal |
| UDP | ipsec-nat-t | IPsec NAT-Traversal |