Which vpn protocol should I use?
It depends a lot factors like ISP, the goal of using vpn, level of security, the speed you want, etc.
Which vpn protocol upi can use?
The best vpn protocol is: IKEv2, OpenVPN, Cisco VPN, Kerio, IPSec, PPTP , L2TP
And the best vpn in Speed: IKEv2, PPTP, IPSec, Cisco, Kerio, …
the best vpn service in security: Ikev2, IPSec, Cisco VPN, OpenVPNThe above protocols is one standard setting them up, but sometimes the vpn providers change the config on the protocol and make a strong vpn protocol with wraped encrypted at rapid speed like Potent VPN App that is a type of new and proffesinal OpenVPN and you only use it by the vpn App.
And please note you sometimes have to use the vpn according your ISP. the ISP is same the internet you are connecting on.
Some ISP has no limitation on ports and you can connect the vpn easily.
And others have a high or medium limitation like China or Iran.
Two best vpn providers which provide all VPN protocols, are Potent VPN and Noodle VPN,
that vpn users can connect the vpn by any protocols they like.
Buy VPN and access all vpn protocols by Potent VPN. Better connect the vpn app that providing by potentvpn.