In a failover configuration with Cisco Secure Firewall Threat Defense (FTD) devices, ensuring that users on the internal network can continue to communicate with outside devices if the primary device (FTD1) fails requires the implementation of a stateful failover link. The stateful failover link allows the secondary device (FTD2) to maintain session information and state data, ensuring seamless failover and minimizing disruptions.
Steps to implement a stateful failover link:
* Physically connect a stateful failover link between FTD1 and FTD2.
* Configure the stateful failover link in the FMC.
* Ensure that both devices are properly synchronized and that stateful failover is enabled.
* Deploy the changes to both FTD devices.
By configuring a stateful link, the secondary FTD can take over active sessions without requiring users to re- establish their connections, thus ensuring continuous communication.
References:Cisco Secure Firewall Threat Defense Configuration Guide, Chapter on Failover Configuration.