تماشای ویدئو Site To Site GRE Tunnel VPN Configuration Between CISCO and Mikrotik Router از آی-ویدئو
Site To Site GRE Tunnel VPN Configuration Between CISCO and Mikrotik Router.
http://mikrotikroutersetup.blogspot.com/2012/10/generic-routing-encapsulation-gre-cisco-mikrotik-router-configuration.html