<Li> SCTP support: IKEv2 allows for the SCTP protocol as used in Internet telephony protocol VoIP . </Li> <Li> Simple message exchange: IKEv2 has one four - message initial exchange mechanism where IKE provided eight distinctly different initial exchange mechanisms, each one of which had slight advantages and disadvantages . </Li> <Li> Fewer cryptographic mechanisms: IKEv2 uses cryptographic mechanisms to protect its packets that are very similar to what IPsec Encapsulating Security Payload (ESP) uses to protect the IPsec packets . This led to simpler implementations and certifications for Common Criteria and FIPS 140 - 2, which require each cryptographic implementation to be separately validated . </Li> <Li> Reliability and State management: IKEv2 uses sequence numbers and acknowledgments to provide reliability and mandates some error processing logistics and shared state management . IKE could end up in a dead state due to the lack of such reliability measures, where both parties were expecting the other to initiate an action - which never eventuated . Work arounds (such as Dead - Peer - Detection) were developed but not standardized . This meant that different implementations of work - arounds were not always compatible . </Li>

What does the ikev2 protocol require in order to obtain and use a certificate