Using pfSense to pûblic IP a 3G network
I have a site underconstruction where the only way I have to get internet is a 3G connection, so far not issue… But I need to access this network from internet... So far I do have a pfSense on the remote LAN connected to another VM pfsense (which has a leg on a Public IP) via a Open VPN
something like : internet <-> pfSense VM W/pubic IP <-openVPN-> psFense router over 4G
I am not sure if there is an way to do some NAT from the public IP to the remote site, like to be able to SSH 10.10.10.200 via 151.15.x.x...
Cellular ISP does carrier grade NAT within their network. Cell connections are generally not on connectable public IPs.
You shouldn't need any NAT on your side to get a site to site connection working
a) pfsense VM as OpenVPN server peer-to-peer on a regular fixed connection (fibre/cable/dsl)
Can be with public IP (bridge mode), or port 1194 udp forwarded from ISP side router
b) pfSense router behind 4G connection, as Open VPN client, peer-to-peer.
b) connects a), and maintains the connection, over 4G , 3G, whatever.
You can access all of b)'s network from a), or even do a NAT port forward on pfsense a) to any b) address.