Internet Key Exchange
Version 2 (IKEv2), a next-generation key management protocol based on RFC 4306,
is an enhancement of the IKE Protocol. IKEv2 is used for performing mutual
authentication and establishing and maintaining security associations (SAs).
FlexVPN is Cisco's
implementation of the IKEv2 standard featuring a unified paradigm and CLI that
combines site to site, remote access, hub and spoke topologies and partial
meshes (spoke to spoke direct). FlexVPN offers a simple but modular framework
that extensively uses the tunnel interface paradigm while remaining compatible
with legacy VPN implementations using crypto maps.
This guide contains
the following modules:
Configuring Internet Key
Exchange Version 2 (IKEv2) and FlexVPN Remote Access
This module describes
IKEv2 CLI and is divided into basic and advanced sections.
The basic section
introduces basic IKEv2 commands and describes IKEv2 smart defaults and the
mandatory IKEv2 commands required for FlexVPN remote access. This module is a
prerequisite for understanding subsequent chapters.
The advanced section
describes global IKEv2 commands and how to override the default IKEv2 commands.
Configuring FlexVPN Server
This module describes FlexVPN server features, IKEv2 commands required to configure FlexVPN server, remote access clients
and the supported RADIUS attributes.
Configuring FlexVPN Client
This module describes FlexVPN client features and the IKEv2 commands required for FlexVPN client.
Configuring IKEv2 Load Balancer
This module describes the IKEv2 Load Balancer Support feature and the IKEv2 commands required to configure the IKEv2 Load
Configuring IKEv2 Fragmentation
The IKE Fragmentation adhering to RFC feature
implements fragmentation of Internet Key Exchange Version 2 (IKEv2) packets as
proposed in the IETF
The IOS IKEv2 support for AutoReconnect feature of AnyConnect
feature helps in reestablishing IKEv2 negotiation without user interaction with
the Cisco AnyConnect client.
Packet of Disconnect
The IKEv2 Remote Access Change of Authorization (CoA)—Packet of
Disconnect feature terminates an active crypto IKEv2 session on Cisco supported
Change of Authorization Support
The FlexVPN - IKEv2 CoA for QoS and ACL feature supports RADIUS
Change of Authorization (CoA) on an active IKEv2 crypto session.
The FlexVPN RA - Aggregate Auth Support for AnyConnect feature
implements aggregate authentication method by extending support for Cisco
AnyConnect client that uses the proprietary AnyConnect EAP authentication
method to establish a secure tunnel over the Internet between Cisco AnyConnect
client and FlexVPN server.
Appendix: FlexVPN RADIUS Attributes
This module describes the RADIUS attributes supported by FlexVPN server.
Appendix: IKEv2 and Legacy VPNs
This module contains configuration examples on how to configure legacy VPNs such as crypto maps and DMVPN with Internet Key
Exchange Version 2 (IKEv2).