How to enable NAT Traversal on IOS router/firewall?

[jasonhumes]

I need to enable NAT Traversal on my IOS firewall so that my vpn clients who are trying to connect from behind a pix can connect and communicate properly. How can I do this? On a pix its 'isakmp nat-traversal'...but i cant figure it out on the router. Please help. Thanks.

[wyatts]

http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chapter09186a0080455c72.html

Configuring NAT Traversal

NAT Traversal is a feature that is auto detected by VPN devices. There are no configuration steps for a router running Cisco IOS Release 12.2(13)T. If both VPN devices are NAT-T capable, NAT Traversal is auto detected and auto negotiated.

Disabling NAT Traversal

You may wish to disable NAT traversal if you already know that your network uses IPSec-awareness NAT (spi-matching scheme). To disable NAT traversal, use the following commands:

SUMMARY STEPS:

1. enable

2. configure terminal

3. no crypto ipsec nat-transparency udp-encapsulation