I have from my isp a static ip X.X.X.X and an unrouted public subnet Y.Y.Y.0/24 registred at ripe.
An ex-coworker of mine setup a server that does the routing which have te folowing config:
ISP------->(eth0) Server (eth1)--->Switch---> Multiple pc X.X.X.X eth0 : X.X.X.X Static ip: Y.Y.Y.100-150 (each pc have its own public ip) eth1:2 : Y.Y.Y.1 Gateway : Y.Y.Y.1 eth1:3 : Y.Y.Y.2 eth1:4 : Y.Y.Y.3
Once I changed my plan to 10Gpbs (Internet in Romania is dirt cheap) the server was deprecated so we bougnt a new capable one. I can't find on internet how to setup the new one to do exactly the same thing as the old one.... Most of the ISPs route the subnet themselves but mine doesn't. When I called my ISP for help their answer was: "Deal with it! Search on google !"