Throughout the documentation, available on NETGEARs website, the power supply voltage range is not specified - only the output voltage of the enclosed wall socket power adapter (12V).
What I meant was - what is the power supply voltage range for the GS105? The inlet is marked 12 VDC but the allowed input v-range is not specified anywere.
I can't speak for Netgear but they probably don't support using anything other than the supply that it ships with.
However, it will probably work. I have had the FS105 running on the 12Volt system on my boat for a year now, and some times the voltage has gone has high as 15.5V and below 12.0V it has worked with no apparent problems.
Personally, I would just try it. I have have GS305 in the post, and if it breaks as a result of me powering this way then I've lost £18 - I've been doing this sort of thing for years and never had a problem yet so £18 is a small risk in that context.
If you considering doing this with more expensive equipment I would consider looking into a installing a regulated 12V feed for example something based on the LM2577 regulator which can handle the input voltage going either lower or higher than the target voltage.
