Clock signal becomes noisier at higher frequencies
Fist, a 200 MHz oscilloscope and a 200 MHz probe will only give you a system bandwidth of 141 MHz (ish).

We talk about calculating "system bandwidth" on our blog here:
https://community.keysight.com/community/keysight-blogs/oscilloscopes/blog/2016/09/01/what-is-oscilloscope-system-bandwidth-and-how-do-i-find-the-bandwidth-of-the-scope-probe

Basically, the bandwidths compound.

Second, a bandwidth of 141 MHz means you can a 141 MHz sine wave with 3dB or less of attenuation. So, for a 100 MHz clock, it's not going to look like a square wave.

This app note actually looks at a 100 MHz clock example on page 7 and talks about how to evaluate your oscilloscope's bandwidth for your app.

http://literature.cdn.keysight.com/litweb/pdf/5989-5733EN.pdf 

The ringing you're seeing is probably some inductive or capacitive effects of your probing system.