Webpages on server work sometimes and some times not

Hello guys,

I am experiencing a weird problem with my ISPconfig 3 server.

Where I am always able to view any website when I type the url into the browser, many people cannot see anything and the page hangs on loading.

Without touching anything the problem is fixed and after a while (hours, days, weeks) it does the same problem.

I would appreciate some troubleshooting since I have no idea why what and where can this possibly been caused from.

Thanks

 

This could be a DNS problem.

Have a look at all your DNS'ses pointing to the domain in question, and see if they are setup okay.

 

If who live in europe, some Dns servers kick you out, if your dns servers are not allways connected.