 AuthIP adds a second authentication to the standard IKE authentication which, according to Microsoft, increases security and deployability of IPsec VPNs.AuthIP adds support for user-based authentication by using Kerberos v5 or SSL certificates.AuthIP is not compatible with IKEv2, an IETF standard with similar characteristics; however Windows 7 and Windows Server 2008 R2 also support IKEv2.