Boundary Conditions - Half of a cylinder

[Max]

Hello everybody,
I have a quick question about the boundary conditions. I cant seem to find the right tool to fix (all DOF to 0) the bottom half of my cylinder (pictures attached with the area marked in red). The only way i can think of is to create a surface in which i select each node inidivdually and the fix that surface but there has to be a better way?

Thanks in advance.
Greetings

[FEAnalyst]

It would be best to have a surface partition prepared in CAD before importing to PrePoMax but you can also just create a node set using the Face angle (if only the surface nodes should be selected) and Node modes of FE mesh based selection and drag the selection box over that half of the cylinder.

[Max]

Thank you very much.