Updating zone file serial number convention speeddating chicago il
When configuring BIND, all times are specified in seconds. However, it is possible to use abbreviations when specifying units of time other than seconds, such as minutes ( Seen individually, directives and resource records can be difficult to grasp. ( 2001062501 ; serial 21600 ; refresh after 6 hours 3600 ; retry after 1 hour 604800 ; expire after 1 week 86400 ) ; minimum TTL of 1 day IN NS dns1. A slave (Secondary) DNS server will read the master DNS SOA record periodically, either on expiry of refresh (defined below) or when it receives a NOTIFY and compares, arithmetically, its current value of sn with that received from the master.If the sn value from the master is arithmetically HIGHER than that currently stored by the slave then a zone transfer (AXFR/IXFR) is initiated by the slave.The email address of a suitable DNS admin but more commonly the technical contact for the domain.By convention (in RFC 2142) it is suggested that the reserved mailbox hostmaster be used for this purpose but any sensible and stable email address will work.
If the name server is within this domain (in this zone file) it can be written as ns1 (without the dot) which will be expanded to include the $ORIGIN.
Using this date format convention the value 2005021002 indicates the last update was on the 10th February 2005 and it was the third update that day.
The date format is just a convention, not a requirement, so BIND (or any other DNS software) will not validate the contents of this field.
NOTE: Format is mailbox-name.domain.com, for example, hostmaster.(uses a dot not the more normal @ sign, since @ has other uses in the zone file) but mail is sent to [email protected]
Most commonly ending with a '.' (dot) but if the email address lies within this domain you can just use hostmaster (see also example below). Unsigned 32 bit value in range 1 to 4294967295 with a maximum increment of 2147483647.