The side of the switch has different sets of holes for attaching mounting brackets in either configuration.
Brackets for a two-post mount are not included in the box with your switch. However, they can be ordered separately using part number XN-2P-RKMT299.
To attach your switch to a two-post rack, follow these steps:
If the switch cannot be tilted (because other equipment is mounted directly above and below), remove one or both short mounting brackets from the switch. Lift the switch into position, secure the flanges (ears) on the long brackets to the rack posts, and then reattach the short brackets.
If your switch comes with installed AC power supplies, skip to Turn on the Switch.
If your switch does not have an installed power supply, install one or two power supplies using the instructions in Installing Internal Power Supplies.