Disabling NAT in a VPN Tunnel
When communicating within a VPN, it is normally not necessary to perform NAT.
You can disable NAT in a VPN tunnel with a single click in the VPN community object.
Disabling NAT in a VPN tunnel by defining a NAT rule Set of traffic parameters and other conditions in a Rule Base (Security Policy) that cause specified actions to be taken for a communication session. slows down the performance of the VPN.