Peplink (MAX Pro 5g) IPSec vpn cellular to Fortinet VPNC

Product Discussion Pepwave MAX
1

I am having trouble settiing up an IPSec VPN between Peplink 5G device and a Fortinet FW/VPNC.

Using DDNS with WAN link cellular (5G) as primary (and only) WAN link.

VPN in routed mode on both ends,
IKEv1
aggressive mode since dyndns is used
PSK

The device has no issues for normal connectivity (internet) thru cellular
IKE phase is working, but it never gets to second phase.

Any clues? How can check/debug on the Peplink device what is actually happening?

Anyone has this setup running? Or similar setup?

2

We do have several setups running with similar but other brand 4g routers with no issues at all

3

I will be testing with decreasing the mtu size and update the results

4

no result