On Mar 6, 7:04 pm, Paul wrote:
And I've never lost a dialupmodem, or an ADSLmodem, and I've been here for
twenty years, so something must be protecting me.

Destructive transients are typically once every seven years. A
number that varies significantly even within the same town.

DC paths are obviously irrelevant. Critical is a 'low impedance'
connection to earth. Direct Current and low impedance define two
different conditions. Why must a telco installed protector must be
connected 'less than 10 feet' to the single point earth ground? Every
word in that sentence has serious technical significance.

All electronics contain serious protection. For example, an
Ethernet port on that DSL modem is rated at least 2000 volts. The OP
and others are reminded: any subjective recommendation (no numbers) is
best considered erroneous or deceptive. Anyone who recommends
protection should even know that 2000 volt number. No numbers quickly
separates myths from science.

Meanwhile, the topic is damage created by a power “outage”. A
solution designed for 'thousands of volt' transients does nothing when
AC electric drops to zero volts. Other anomalies might explain modem
damage should the OP desire solutions. That power strip is not a
useful solution.