When do you get the 'climb up' prompt?

[eberkain]

I don't get the option to climb here.  

Is it only for specific parts?  Even using the ladder I don't get an option to climb up onto the platform.  Its a little frustrating. 

[InfernoSD]

I don't think it looks for specific parts. I think it looks for any solid object within a certain space above and in front of the kerbal, and in fact it often misses what you would expect to be a good platform. In this case I would simply press jump and then mash the climb button. Usually does the trick.

[jimmymcgoochie]

I’m not sure that grip strips are climbable, but just jump and the structural plates should let you climb on them.