6 Appendix A: Product Behavior
The information in this specification is applicable to the following Microsoft products or supplemental software. References to product versions include updates to those products.
Windows NT operating system
Windows 2000 operating system
Windows Server 2003 operating system
Windows XP operating system
Windows Vista operating system
Windows Server 2008 operating system
Windows 7 operating system
Windows Server 2008 R2 operating system
Windows 8 operating system
Windows Server 2012 operating system
Windows 8.1 operating system
Windows Server 2012 R2 operating system
Windows 10 operating system
Windows Server 2016 operating system
Windows Server operating system
Windows Server 2019 operating system
Windows Server 2022 operating system
Windows 11 operating system
Windows Server 2025 operating system
Exceptions, if any, are noted in this section. If an update version, service pack or Knowledge Base (KB) number appears with a product name, the behavior changed in that update. The new behavior also applies to subsequent updates unless otherwise specified. If a product edition appears with the product version, behavior is different in that product edition.
Unless otherwise specified, any statement of optional behavior in this specification that is prescribed using the terms "SHOULD" or "SHOULD NOT" implies product behavior in accordance with the SHOULD or SHOULD NOT prescription. Unless otherwise specified, the term "MAY" implies that the product does not follow the prescription.
<1> Section 2.2: On an EAP server, Windows initializes the EAP Identifier to zero for the first EAP identity request packet of an EAP session (as specified in [RFC3748]). From here on, for all the subsequent EAP Request messages, the Identifier is incremented by one. The peer uses the same identifier it received in the request packet for the EAP response packet (as specified in [RFC3748]).
<2> Section 3.2.3: On a peer, Windows maintains a configuration that specifies whether the Extensible Authentication Protocol Method for Microsoft CHAP is to be used.
<3> Section 3.2.4: On a peer, Windows invokes a user interface to accept the credentials from the user, and if they are provided, message processing continues. Trigger the transport layer with the authentication result as Failed, if the user cancels the authentication.
<4> Section 3.2.5.2: On a peer, Windows invokes a user interface to accept the credentials from the user, and if they are provided, message processing continues. Trigger the transport layer with the authentication result as Failed, if the user cancels the authentication.
<5> Section 3.3.4: On an EAP server, Windows maintains a list of configured EAP methods that are supported and determines if the Extensible Authentication Protocol Method for Microsoft CHAP is supported.
<6> Section 3.3.5.2: On a server, when validation fails, Windows sends an EAP Failure packet.
<7> Section 3.3.5.4: On a server, when validation fails, Windows sends an EAP Failure packet.