The Complete Cisco VPN Configuration Guide

IPsec Remote Access and L2L Sessions on the Same Router

Figure 18-3 shows an example network that has both remote access and L2L sessions. In this example, the remote office network is acquiring its address dynamically, via DHCP, from its connected ISP, which also is true of the remote access clients. Because the central office router doesn’t know the remote office router’s IP address, you would have to configure the pre-shared key for the router as 0.0.0.0 0.0.0.0 with no XAUTH. However, doing this would cause XAUTH to not work for the remote access clients. One solution would be to use certificates instead of pre-shared keys; for small networks, though, this might not be cost-effective or practical.

Figure 18-3. Remote Access and L2L Connections ...