Bind updating serial number for zones ms oriental dating service
It's so that other servers doing zone transfers can verify if they need to do a zone transfer. Most Zone files are just text files in the *nix world.Normal convention is that the Serial number is the timestamp in date ISO date format followed by a two number increment 2014101501 Microsoft products are set up to autoincrement the Serial Number when changes are made.When you use a fancy DNS server, which has a database backend for intance, it can compute the serial number automatically (which is usually in the tool from ndu (that tool does not require BIND).When you run it on a zone file, it updates the serial number with the current date, and even handles the last two digits (a simple counter).Googling around for answers, I found the following explanation: Serial numbers in DNS zone files provide a way for the server to verify that the contents of a particular zone file are up-to-date.
A nice HOWTO about this is at: is also the recommended way in the DNS & BIND book (2006 ed.).Once the zone transfer has been received and the zone has been updated, then this zone refresh is complete - named does not continue to try the other servers to see if one of them has a yet bigger SOA.The frequency with which this type of refresh takes place is controlled by the settings in the zone's SOA record.The term 'masters' here doesn't mean that the servers listed have to have the zone configured as 'master' - it just means that these servers so listed are authoritative for the zone and can provide a zone update if one is requested of them.Slave servers can provide zone updates to other slaves.
If you work with the DNS server bind you'll probably be used to updating the serial number for your zone files manually after making changes.