Since no one makes a rack mount cable modem I made my own. : r/homelab
Rack Mount Shelf - Aurora Australis Network
Arris Surfboard Modem Rack Mount Fan by Capra-Audio | Download free STL model | Printables.com
Hiltron or Spectrum E31T2V1 / E31N2V1 / E31U2V1 Cable Modem 2U Rack Mount - Etsy UK
DB-CMTS8100 DOCSIS 3.0 1U mini CMTS| Alibaba.com
I'll see your cable modem and raise 1U! : r/homelab
Bulk Buy China Wholesale Docsis 3.0 1u Rack Mount Internet Access Services With Quality, Cost And Reliability from Chongqing Jinghong Hi-Tech Co. Ltd | Globalsources.com