One thing that was over looked by the other administrators, the IPSEC-GW needs the proper keyid value and not FQDN or username during IKEv1 setup. You can have all of the correct auth/encryption proposals defined, and the proper localid ( aka group_name ) , but if the responder is expecting a FQDN, the fortiClient will not work in most cases.
This two screen shows will show the fortiClient and the idtype value of keyid vrs FQDN capture from a tcpdump
So if you have a ipsec-gateway set the group idtype to be keyid if you want to use the fortiClient.
On a Fortigate appliance they typically don't care and use a type of "any" unless you hard code it.
NOTE: these values are sent in the clear & when IKEv1 is being used along with aggressive-mode, this is why ikescan attacks and weak PreShareKeys are quick to be brute-force. So if you use IKEv1 , try to set very long pre-share-keys and if your using XAUTH for dynamic-remote users, very long password or even better a hybrid of PSK+XAUTH+MFA
NSE ( network security expert) and Route/Switching Engineer
kfelix -----a----t---- socpuppets ---dot---com
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