I recently deployed a UC560 box for a client, the client uses a modem that assigns ip address and dns addresses to it automatically. Initially everything was fine, the PC's on the LAN were all browsing, but two days ago, i got a call and was told the PCs could no longer browse the internet, i did all the checks everything was fine, so i decided to ping the dns ip addresses, no replies. When i connected a laptop directly to the ISP modem, it browses fine. But i still could not ping the dns addresses from the laptop. Please what could be the issue?