Summary

The provided scenarios reflect about 90 percent of the problems you face with Cisco's RA VPN solutions. This chapter is based on real world examples; everything you just read has been used in real situations. The chapter covers the following:

• VPN 3000 software client Several scenarios and cases on troubleshooting VPN client problems.

• MTU How crucial the MTU is in regards to VPN and several methods to lower it.

• Software firewalls Troubleshooting problems with the VPN client and some of the better-known software firewalls in the market, such as ZoneAlarm.

• DNE What DNE is and its function with VPN.

• PPPoE What PPPoE is and how to get VPN to work several of the commonly used PPPoE clients.

• VPN 3002 Hardware client How to troubleshoot some of the larger problems.

As previously stated, this part does not include solutions that are not specifically for enterprise remote access use. This part does not include any recently announced solutions or expected standards because they are not implemented, and consequently, there is no available information for possible troubleshooting issues. The information provided in Part V, "VPN" reflects troubleshooting practices for remote access VPN solutions that are currently in production at the time of writing this book.