Can't Get Routers To Work With ISP

I've never had this problem before with my ISP (Knology).But supposedly they had a scheduled maintenance real early this morning before 6 AM.Well, ever sense they did maintenance the router will not work and neither will my old one. The new router is a netgear, the old one is a linksys.I called them a few times and everything they had me try did not fix the problem.I can get internet access connected directly to the modem just can't get the router to work.When I right click and diagnose the problem it tells me that it's a connectivity issue with the modem. When I use my old linksys router and diagnose the problem it tells me that the DNS server is not responding.I have also tried resetting the new and old routers to default settings and started fresh.