Set the VPN IKE IDs and use Main Mode
Solutions with a NAT device in the tunnel path need to have IKE IDs specified. For all solutions, we recommend using Main mode instead of the default Aggressive mode. This section describes how to set both of these.
1.Specify the Local and Peer IKE IDs
On the VPN > Settings page, click on the icon of a note and pencil at the right of the AlliedTelesis policy’s entry. The VPN policy dialog box opens.
On the General tab, enter the Local and Peer IKE IDs. Select “type” of Domain Name. The values do not have to be real domain names, but must match the values on your Allied Telesis router (remember that “local” on the SonicWALL is “remote” on the Allied Telesis, and so on).
Page 27 AlliedWare™ OS How To Note: VPNs with SonicWALL routers