Ask the Expert

Can you explain many-to-one address translation?

Can you explain many-to-one address translation?

    Requires Free Membership to View

In many-to-one address translation AKA-PAT/NAPT (Port Address Translation), the IP address and source IKE port, normally User Datagram Protocol (UDP) port changes. Some VPN devices do not support IKE requests sourced on these ports and devices performing many-to-one NAT do not handle ESP or AH correctly. FYI- ESP and AH are higher-layer protocols on top of IP that do not use ports.

Since many-to-one address translation is common with many environments where remote-access clients are deployed, a special mechanism called NAT transparency exists to overcome these NAT issues. NAT transparency NAT-t re-encapsulates the IKE and ESP packets into another transport layer protocol, such as UDP or TCP, which enables address-translating devices to perform translation correctly. Learn more about NAT-t here.

Also, here's a very good article by Lisa Phifer on NAT & IPSEC issues.

This was first published in October 2004

There are Comments. Add yours.

 
TIP: Want to include a code block in your comment? Use <pre> or <code> tags around the desired text. Ex: <code>insert code</code>

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
Sort by: OldestNewest

Forgot Password?

No problem! Submit your e-mail address below. We'll send you an email containing your password.

Your password has been sent to: