Help with installing rack mount chassis and rails

muell

Ive had my rack for a little while. Ive been using it for my ccna lab but i just recently got my first rack mount computer chassis and rails. I think im either doing something stupid or this is just the way it is but I dont think the rails are supposed to mount to the front of the rack but im not sure how to mount them to the back of the legs when using cage nuts. The other issue is the rails only mount at one height on the side of the chassis but if I mount them there the holes int the ears on the case dont line up with the rack. Not that it matters because I couldnt push it all the way back anyway because the ear on the rail is in the way. What am I doing wrong?


chassis: CHENBRO RM41300-FS81 Black Steel / Plastic 4U Rackmount Server Case for Tesla GPU 3 External 5.25" Drive Bays - Newegg.com


rails: CHENBRO 84H342310-001 Slide Rails - Newegg.com