I have a branch office that needs voice communication with the headquarter, so we put there a 2801 with an FXO port and a analogic pone device.
Then I configured a ASA in the headquarter as EzVPN server and configured the 2801 as EzVPN client.
The problem is that for a router to be an EzVPN client it needs 2 interfaces to be configured, one as VPN outside and the other one as VPN inside, and when the traffic comes from the VPN inside interface and goes to the outside the router cryptographs it and send through the tunnel. My problem is that there is no traffic comming from the inside interface, it's beeing generated by the router by itself.
For the router accept the configuration I have configured a loopback as the VPN inside. If i issue a ping with the source keyword and set the loopback as the source the traffic goes through but the phone does't work because the router sets the ethernet as the origem of the traffic. So is there some way to make the router have the source always in the loopback?