Chapter 14. Troubleshooting IPsec VPNs
When crypto is configured on Cisco IOS, at a minimum several components are used, such as IP connectivity, IKEv2, IPsec and GRE encapsulation. All these technologies are complex and often are made up of a number of components themselves. Having a base knowledge of how the protocol or feature in question operates will always help in any troubleshooting situation.
Many designers and administrators of VPN technologies soon become lost when issues occur; however, by following some simple steps they can usually find the root cause of the issue in a timely manner. If the root cause cannot be found, following a proven methodology will allow the area of issue to be determined, so it can then be examined ...