I finally took it over to make my system even slightly better in terms of security, and installed a router with firewall capabilities. Nothing goes as planned, not with IT, at least. Practically whole weekend was ruined, as I was installing, rebooting, reconfiguring in an endless loop. This time the error conditions had a sort of surreal beauty with them: system seemed to work or not work with random sites and services, simply at whim. Phoned my ISP service number, and just after half an hour of queuing (oh, perhaps 45 mins), and with no help, I return home and reboot, just to find everything miraculously working again. Reading the router system logs, the lullaby of electronic times?