Wandboard Quad on Arch Linux can't be pinged

Hello to all. My Wandboard Quad is refusing to be pinged. It’s not visible to Windows (Windows 7 64), but my router can see it, but lists it as not responding. However I can connect via the serial port and log in. But what Linux I know has gotten rusty. Can anyone help me find out exactly why it’s refusing to respond to the pings?

I’ll be happy to supply any info you need.

TIA
Les