I am setting up a VPN server using OpenVPN. The authentication method is the certificate one (different certs for client and server). The VPS has 1TB of traffic monthly.
I plan allowing up to 4 clients per one server. So I'd like to restrict the client using more than 250GB per month.
I thought I might have restricted the amount of traffic coming from one IP, but this idea wouldn't solve the problem - clients may login from either their phone, PC, or tablet.
Ideally, I expect a statement in the .ovpn client file which would be able to control the amount of traffic coming from one client. I haven't found it, though.
How to setup the restriction? Thanks.