Establish multiple IPsec VPN remote access via single WAN on FG

hi,

have a look at, 

https://community.fortinet.com/t5/FortiGate/Technical-Tip-How-to-use-Peer-IDs-to-select-an-IPsec-dialup/ta-p/192292 

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Use-of-PeerID-and-LocalID-in-IPsec-VPN-between-two/ta-p/196761 

for IKEv2 you would need EMS in order to set local id in FCT, if i recall correctly.

For IKEv2, have a look at this recipe:

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Using-Local-ID-for-easier-identification-of-spoke/ta-p/417470

From FortiClient v7.4.4 on, IKEv1 is no longer supported (as mentioned in the forum these days). So, a change to IKEv2 is due anyway.