Port 4500 · IPSec NAT Traversal

Port 4500 is IPSec NAT Traversal, UDP.

IPSec NAT-T — wraps ESP in UDP so IPSec can traverse NAT. Used alongside IKE on 500.

Palo Alto

Create the service object for this port, then allow the App-ID on it. Restricting the rule to the port's service object keeps the rule working on a non-default port and stops the App-ID matching on other ports. Replace the placeholders with your own rule name and zones.

set service udp-4500 protocol udp port 4500

set rulebase security rules <rule-name> from <from-zone> to <to-zone> source any destination any application ike service udp-4500 action allow

Risk and exposure

Rated low risk. Even so, only expose this port to the networks and hosts that need it, and keep it patched.

Check it

• Linux ss -ulnp | grep :4500
• nmap nmap -sU -p 4500 <host>

Related ports

• 3478 STUN / TURN
• 500 IKE / ISAKMP
• 1701 L2TP
• 4501 GlobalProtect IPSec
• 1194 OpenVPN
• 1723 PPTP

← Search all ports