internal subnet of a tunnel vpn equal to my internal subnet

[fabiofabio]

hi,
I have a supplier to which I have to connect with a vpn tunnel that uses the same subnet as other systems that we already have in production on site, how can I hide their internal ip from ours with a subnet that I decide, so as not to have ip conflicts?
I have never dealt with the nat part, but I don't think this is the case to use it, right? in the sense: if I hide an ip with hide nat, it will do the same with both my systems and those of the vpn, right?
any suggestions are well appreciated, thanks.

[Kryten]

I think NAT is the way to go here, at least that is what I did with a different Vendor when this situation came up. It does not need to be hide NAT though, just a static NAT for the remote network to something not in use on your side should be enough. (ideally with the same subnet mask). Of course the other side would need to do the same.