What is Stateful NAT (SNAT)?
A. SNAT allows two or more network address translators to function as a translation group. One member of the translation group handles traffic requiring translation of IP address information. Additionally, it informs the backup translator of active flows as they occur. The backup translator can then use information from the active translator to prepare duplicate translation table entries. Therefore, if the active translator is hindered by a critical failure, the traffic can rapidly be switched to the backup. The traffic flow continues since the same network address translations are used and the state of those translations has been previously defined. Refer to Enhanced IP Resiliency Using Cisco Stateful NAT for more information.
