If you encounter Proxy Authentication Error 2606 in OneDrive and your client is unable to connect to Microsoft server, check out these solutions.

See this post if there is a problem with the proxy server's security certificate when Outlook tries to connect to a server. Working fixes here!

Had to read that a few times... perhaps you have DHCP set up for the local boxes, rather than static IP's?<BR><BR>I'd try to turn sharing off, see if your cable/dsl can still connect w/o errors ...