GRC | Port Authority, for Internet Port 500

Port Authority Edition – Internet Vulnerability Profiling
by Steve Gibson, Gibson Research Corporation.

Goto Port 499

Probe Port 500


Enter Port: 0-65535

Goto Port 501

Port Authority Database

Port 500

Name:	isakmp
Purpose:	Internet Security Association and Key Management Protocol (ISAKMP)
Description:	Port 500 is used by the Internet key exchange (IKE) that occurs during the establishment of secure VPN tunnels. Users of VPN servers and clients may encounter this port.
Related Ports:	-

Background and Additional Information:

Port 500 is used by most IPSEC-based VPN systems for the establishment of securely encrypted "tunnels" between endpoint machines. Users of firewalls or routers that must pass or negotiate VPN connections may need to allow UDP traffic to cross on port 500.

ISAKMP RFC:

http://www.ietf.org/rfc/rfc2408.txt

http://www.faqs.org/rfcs/rfc2408.html

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