[Resolved]  BSNL Broadband — Some sites do not open

I host a number of websites on Midphase, a reputable hosting company, in all the years i have been hosting with them I have had no problems that they have not fixed quickly. Recently I have been unable to view my sites and all my clients using BSNL are also unable to do so. I have discovered that this is because there is something drastically wrong with BSNL's DNS settings and can be avoided by changing the DNS settings on a computer to match those on OpenDNS. however it is not possible to tell all the people who routinely access my sites to do this and it has damaged my business considerably.