After completing this chapter, you will be able to perform the following tasks:
Differentiate between initial and ongoing VPN failures
Troubleshoot remote-access VPNs
Troubleshoot LAN-to-LAN VPNs
Troubleshoot preshared key and CA-based VPNs
This chapter looks at simple virtual private network (VPN) troubleshooting. It covers remote-access VPNs and LAN-to-LAN VPNs using preshared keys and digital certificates. The chapter starts by covering the basic failures that can apply to all VPNs: initial failures and ongoing failures. Most of the time, you will experience initial failures. These are failures to get the VPN established after the initial configuration. This is quite normal, because VPN configuration is tricky. I cannot ...