This subcategory reports the results of AuthIP during Extended Mode negotiations. Events for this subcategory include: ? 4978: During Extended Mode negotiation, IPsec received an invalid negotiation packet. If this problem persists, it could indicate a network issue or an attempt to modify or replay this negotiation. ? 4979: IPsec Main Mode and Extended Mode security associations were established. ? 4980: IPsec Main Mode and Extended Mode security associations were established. ? 4981: IPsec Main Mode and Extended Mode security associations were established. ? 4982: IPsec Main Mode and Extended Mode security associations were established. ? 4983: An IPsec Extended Mode negotiation failed. The corresponding Main Mode security association has been deleted. ? 4984: An IPsec Extended Mode negotiation failed. The corresponding Main Mode security association has been deleted. Refer to the Microsoft Knowledgebase article ?Description of security events in Windows Vista and in Windows Server 2008? for the most recent information about this setting: http://support.microsoft.com/default.aspx/kb/947226. Fix: (1) GPO: Computer Configuration\Windows Settings\Security Settings\Advanced Audit Policy Configuration\Audit Policies\Logon/Logoff!Audit Policy: Logon-Logoff: IPsec Extended Mode (2) REG: NO REGISTRY INFO