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Monitor your cable modem with Zabbix

6 min readJun 22, 2025

Sometimes I start things and don’t finish them. Monitoring my cable modem was one of those projects I started in 2020 and never finished. I was able to write a simple postman collection to retrieve data from a few of the pages on my MB8600, but I never integrated into my monitoring infrastructure. I revisited this project recently as I was having issues with my cable modem and tried a few things to resolve the issue. Fundamentally a reboot of the device resolved it (I was experiencing slowness in my downloads likely due to a recent outage that caused my downstream carriers to be in a bad state). I’m hoping that the next time I have issues, this monitoring will allow me to resolve it more quickly.

Data Over Cable Service Interface Specification (DOCSIS)

Cable modems use a protocol called DOCSIS to communicate and provide data services. Cable modems act as network bridge between your local network and the Hybrid Fiber-Coaxial (HFC) provided by your cable provider to connect you to the internet. The DOCSIS specificaiton has gone through a few iterations and my device is operating at DOCSIS 3.1. Many devices allow for some user adminstration and visibility. My device uses a proprietary protocol call HNAP

Home Network Administration Protocol (HNAP)

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John Wheeler
John Wheeler

Written by John Wheeler

Security professional, Mac enthusiast, writing code when I have to.