Hi,

i have a dual-wan-failover setup here - one uplink is common cable internet, the other one is a SXT LTE Kit from Mikrotik. My cellular provider does not provide public IP addresses for LTE users and uses carrier grade NAT, which is bad. I just want the possibility to access my network in case of a connection failure of WAN1. So, my idea was to create a VPN tunnel between an external linux server and the SXT LTE (no lte passthrough), so that i can login to the linux server and have access to my network from there.
I never used a VPN between Ubuntu Linux and Mikrotik, so i don't know which would work best (IKEv2, PPTP, IPSEC/L2TP, ...)

What would be an easy and secure solution for that requirement ?