Another phone’s hotspot or tethering
No technical countermeasure exists at this layer. A rule that pretends to close this at the router/endpoint the trick operates on is more dangerous than no rule at all, because it can give the family a false sense of coverage. Apply enforcement at the layer that actually carries the traffic or on the device/account directly.
How common it is: not established. No opened high-quality source quantified tethering specifically as a child circumvention technique.
Detection
The controlled device is not associated with the home access point while still showing use; the hotspot-providing device may show hotspot/tethering activity or unusually high data consumption.
Fix (technical)
technically not closable by the home router. Endpoint/account controls must cover the controlled device. A parent who also administers the hotspot-providing device may separately restrict that device,…
Fix (relational)
If access is repeatedly borrowed from another person, discuss what the existing policy prevents and whether the child is relying on peers to meet a social or practical need.
Residual risk
Hotspots supplied by peers or other unmanaged devices remain outside parental administration.
Sources
- rfc9076-dns-privacy