I need assistance selecting the correct vpn technology to meet my requirements.
I have a 2801 router that I will be using to terminate the vpn sessions. I will be using 871 series routers for the remote clients. The requirements that make it difficult for me to determine how to configure are:
The 871 routers WAN ip address will be dynamic, so I cant use standard IPSEC lan to lan configuration. The solution needs to allow the connection from any address.
The remote sites will also need to pass traffic between remote sites. I need to allow this because this VPN is going to be used for IP Phones and I want clients at remote sites to be able to call each other.
Some of the solutions I have seen require the remote user to enter a username and password from the CLI on their 871 to bring up the tunnel. If at all possible I dont want this to be a dependency.
I am familiar with cisco routers and can usually make a config work if provided an example, but I dont know enough about the various VPN options to choose the correct solution. Any help is greatly appreciated.