* What is Perfect Forward Secrecy?
* What is the lifetime of phase 2 tunnel?
* What is the difference between DPD and keepalives in VPN? And which device is enabled by these features by default?

* What is SPI?
* What is invalid SPI Recovery?
* What is compulsory and voluntary tunnel?
* What is the default interval of ISAKMP keepalives?
* In which mode of Phase 1 is ASA enabled by default?
* What is the default ISAKMP policy of ASA?
* Can we terminate VPN on Transparent Firewall?
* What are dynamic crypto maps?
* How many SAs are   formed in Phase 1 and Phase 2 tunnel?

* What is the size of ESP and AH header?

* What are the different types of pre-shared keys?
* What is null encryption in phase 2?
* What is skeyseed?
* Can we do MPF for VPN traffic in ASA?
* Does IKEv1 support compression?