I have very good experiences with the sotm cat7 Ethernet cables, they have a buildin filter:
https://www.sotm-audio.com/sotmwp/english/portfolio-item/dcbl-cat7e/
Also using an isolation trafo is useful:
https://www.sotm-audio.com/sotmwp/english/portfolio-item/iso-cat7/
and of course powering all components in your digital rig with linear power supplies is a must...