IMHO 40 meters with certified Cat. 6A cabling shouldn't be problematic at all WRT interconnecting HPE OfficeConnect 1950's XGE ports to deploy an IRF stack where members are located in different rooms/sites (certified Cat. 6A should let you to cover - at maximum - 100 meters using 10GBASE-T, that threshold falls to 55 meters if Cat. 6 certified cabling is used instead of Cat. 6A).