Well the concept was just to buy the right switch and a suitable USB to DC barrel jack lead; so next to no effort. Unfortunately the OP has gone off track somewhat.

There is no detail on either ASUS's site or the user manual as to how much power the USB ports can supply. I wouldn't be at all surprised to find then only support 0.5 amp and would there probably never be able to power a switch.

I was thinking the same, I have seen USB3 ports that deliver up to 1 Amp but that's not always the case.

Thanks
Dan

In reply to a post by danielhyde:

I was thinking the same, I have seen USB3 ports that deliver up to 1 Amp but that's not always the case.

A USB3 port should be able to deliver 900mA when a USB3 device identifies itself, otherwise it should be a USB2 backwards compatible 500mA. I don't think I've seen a passive cable (e.g. USB to barrel) identify itself as a USB3 device. I've used a few to power fibre convertors in racks !

Yeah, in my personal experience I have a Roku powered from my TV and if I plug it in to the USB2 port it doesn't power up properly but in a USB3 port it works just fine and only has USB2 cable.

Thanks
Dan

In reply to a post by danielhyde:

Yeah, in my personal experience I have a Roku powered from my TV and if I plug it in to the USB2 port it doesn't power up properly but in a USB3 port it works just fine and only has USB2 cable

Without a USB current meter it is hard to tell, but it is possible the USB2 port is under spec and not giving the full 500 mA. Sadly lots are.

its possible to make an un-powered hub from diodes, but this will compromise distance and speed.
http://www.circuit-diagrams.net/page/a-passive-ether...

That’s kinda what I’ve done.

Cheapo netgear switch and a USB to jack (known to work with switch).

I also have a Synology NAS I can draw off

I got a netgear unmanaged switch (5v, .7ma), a USB to jack cable. Plugged into the router, worked straight away.

In reply to a post by MHC:

Unlikely ... it is either one or teh other.

You can get a very small 5 fport switch such as a UniFi FLex Mini for £20

Where'd you see that price?