When it takes more than five seconds to generate a Network Access Protection (NAP) statement of health (SoH) message on a Windows Vista-based computer or on a Windows XP Service Pack 3-based computer, client connections do not authenticate successfully with a Cisco switch.

You cannot connect a computer that is running Windows Vista to a Cisco ASA Series VPN server by using a virtual private network (VPN) connection that is based on the “Layer 2 Tunneling Protocol with IPsec” (L2TP/IPsec) protocol. This problem occurs if another Windows Vista-based computer is already connecting to the VPN server through a L2TP/IPsec-based VPN connection. You cannot connect to the VPN server until the other computer disconnects from the VPN server.

This behavior does not occur on a computer that is running Windows XP or Windows Server 2003.

Consider the following scenario. The network is running a Cisco PIX 515E firewall. A user tries to access a Web page in Windows Internet Explorer 7 by using Security Sockets Layer (SSL) from a computer that is running Windows Vista. However, the user receives the following error message:

Internet Explorer cannot display the webpage

This issue does not occur if the user tries to access the same Web page from a computer that is running Microsoft Windows XP Service Pack 2 (SP2).