Port 4500 supports IPsec NAT traversal and ipsec-nat-t (TCP reference coverage) across distinct transports. Review each protocol before writing firewall or monitoring policy.
Encapsulates IPsec ESP traffic when network address translation is detected.
IPsec NAT traversal endpoints in environments where this service is explicitly configured.
Bidirectional
Pair with a hardened IKE configuration on UDP 500 and restrict peers where topology permits.
ipsec-nat-t (TCP reference coverage) is documented as a network service convention for port 4500 over TCP.
Use this reference entry when identifying or validating systems documented to use 4500/TCP.
Varies
Confirm the listening process and current vendor documentation before permitting traffic; a listed convention does not prove the active service or its security posture.