[Box Backup] BIND serial #

[Marco Bartholomew]

Serial number This value is perhaps the greatest source of DNS-related 
head scratching. To make things fast and efficient, BIND processes zone 
files into another format. When BIND loads a zone file at startup, it 
checks the serial number and only processes the zone file if the serial 
number is bigger than its previously processed version. So, if you 
change the zone file but not the serial number, BIND will ignore the 
changes.

A common format for the serial number contains the date and a unique 
serial number (YYYYMMDDNN) such as 2004010402 for the second revision 
(02) of the file on January 4, 2004. This allows for 100 changes to the 
file in a day. If more changes are required, I recommend going home for 
a good night's sleep.