I have two locally managed DAIP gateways (620 & 730). I need to create a site-to-site VPN between them:
620 -----> NAT device ------> Internet ------> NAT device -----> 730
730 is configured that only remote site opens the connection. 620 is using the hostname to open the connection. Authentication is based on certificates and IKEv1 is used. Using the hostname to connect, NAT-T is not used and so the tunnel is not established. If I temporary change the connection from hostname to IP between static NAT, then the tunnel comes up because NAT-T is used.
My question: how can I force the gateway to use NAT-T when connecting to a hostname instead of an IP?