The cable modem is telco infrastructure that happens to be in your house. The boundary between telco and customer networks (called the &quot;demarc&quot;) is between the cable modem and your router. It&#x27;s entirely theirs to administrator, same as the vault down the street.<p>A comment I posted about this a few years ago: <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=6998650" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=6998650</a>