The good news is that if the DSL or WAN2 light is solid (not off or flashing), it looks as though your internet connection is online.
It may well be that your router has simply "locked up". Please reboot (power off/on) your router.
Please note that rebooting your router WILL cause the DSL or WAN2 light to start flashing as the router attempts to re-establish a connection to the internet.
Once the DSL or WAN2 indicator has stabilised, please check your internet connectivity again.
Did this solve the issue?
Please contact your IT Support Helpdesk immediately as it would seem despite your internet connection being successful there is another problem which they should be able to help you diagnose.