Intermittent connectivity problems

For several months now I have had an issue whereby I loose all internet connectivity and receive DNS errors when trying to browse the internet. Upon phoning the call centre for assistance the issue seems to resolve itself miraculously without the support person making any changes according to them, they apparently only acccess my account to check for errors.<br> <br> Being in IT I know that if there is an issue a change has to be made in order to resolve it. I always do basic error checking myself and first port of call is usually restarting of my rooter. It is now happening regularly that I have to call to have this resolved. I have of course been told I can check on the website which would be great if I had internet connection.<br> <br> This has to be resolved as I am really getting tired of loosing connectivity with no answers on why.