If a MITM attacker is confident they control all paths between a server and a victim, they need not alter IP addresses on packets in transit. To pull this off,

If a MITM attacker is confident they control all paths between a server and a victim, they need not alter IP addresses on packets in transit. To pull this off, the attacker must be near the victim (e.g. compromise a broadband router), thereby reducing the number of targets, or near the server (e.g. compromise every link into a multihomed datacenter), thereby reducing the number of sites intercepted.