Hi Ravi: Each DNS administered unit is referred to as a zone and is managed using a zone file typically. (although you could write all the stuff in one huge file, but that won't scale)
Usually in most DNS setups catering to high traffic nodes, multiple DNS servers are deployed to administer the zones. In event of updates, replication is one mechanism to update the DNS records. However, with large data sets of small updates, (ie. 1000s of changes of one or two lines in the file) a better approach is to update with only the 'diff' as against the full file update. So 'zone distribution' is a technique of distribution of compressed diff files instead of complete zones backed with MD5 checksums. This is a faster and resilient approach. Take a look at the case study by DENIC eG http://www.denic.de/media/pdf/net/part_2-5-b-viii.pdf What is the problem that you are facing ? Which DNS server are you using ? thanks Saifi.
