I am trying to set up a GRE tunnel between two sites. I tried to configure the Netvanta 3430 with the same GRE tunnel settings, other that the ip and gateway for the interfaces, and I am receiving the error "Could not set network interface IP address network mask." I'm not sure what I am missing. Any suggestion or guidance would be appreciated. Also, I need to configure the router so that a SIP phone can connect to an Allworx server at another location as the other 6 offices do.