I am looking to setup a transparent proxy (client) on a computer which will act as a gateway/router for (client) computers connecting to this gateway computer. The client computers use a VPN client which is not going to be modified (nor will it have any proxy client). The transparent proxy client will connect to a proxy (server) through which all traffic (including the VPN traffic) should be routed from. Is this approach even possible with squid or ha proxy?
VPN client on computer -> transparent proxy on computer acting as router/gateway -> proxy on remote server -> VPN server (and the traffic going back the same way).
Any thoughts or suggestions on this matter will be appreciated.