Hello. Say you have a Hub-Spoke network consisting of both a Private IP MPLS network and Public Internet network this and the Hub has a Palo Alto NG firewall
VPN Automated NAT traversal will not work as the PA randomly changes the outbound VPN UDP port. Therefore the remote peers keep sending the to the detination Hub IP but with changing the VPN NAT destination port matched. The PA sees changing ports from the same IP address an intrusion attack and blocks.
VPN Manual port forwarding allows only one Public IP:Port to be set. Therefore the remote peer that has a Private IP MPLS will not attempt to connect to the Hub MX using its internal IP address.
The solution was to create a 1-to-1 NAT on the Hub PA (specific external IP to Hub MX IP (real or virtual) and allow all Meraki VPN UDP ports