VPN Configurations
Clearly, the most detail-oriented and time-consuming portion of configuring VPNs is
ensuring that both peers have matching configurations. This task usually becomes more
complicated because you might have access to only one peer and are relying on someone else
to configure the other end. A single discrepancy between the configurations can prevent the
key exchange from completing or prevent encryption from occurring. It is best to compare
the configurations on both peers before attempting the connection rather than trying to
troubleshoot the VPN after an unsuccessful connection.
In this scenario, you are working as a consultant and have been assigned the task of
configuring a full-mesh VPN between corporate headquarters and two branch offices. Figure
13-10 shows the layout of each network and how the VPNs are to connect.