Bind updating serial number for zones carlos amando dating scammer
A notify is deemed valid if the sender is one of the servers in the NS RRset for the zone, has been explicitly allowed using an 'allow-notify' clause, or is from an address listed in the masters' clause.This seems unintuitive to many when they learn this for the first time, but it vastly simplifies the code/algorithm for handling refreshes on notify and also ensures, by using the same sequence of SOA checks each time, that the slaves will always converge their SOA serial numbers to the most up-to-date version.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.If the serial number in a zone file hasn't changed since that zone was last loaded, named figures that it can ignore the file.Then simply add add, and then remove a temporary record in each zone with nsupdate. is the tool of choice for ignoring serial numbers and just doing it.
The frequency with which this type of refresh takes place is controlled by the settings in the zone's SOA record.
This means that sysadmins have to remember to update the serial number every time they make a change to a zone file -- otherwise, their changes won't be picked up and published.
Source: don't understand this explanation, and the fact that this requires sysadmins to remember to manually update the serial number seems insane. It can't be for DNS servers to verify if a particular record is out-of-date, because that's what the TTL is for. Why not just have the DNS server re-read the zone file when a change is made? The DNS server knows that it needs to re-read the zone file when the serial number changes as just making a change does not trigger anything, there's no timestamp within the zone file generated by changing anything to note that there has been an update on most DNS software.
The only real requirement is that when encoded as a 32-bit integer, the SOA RR serial number field must be incremented when you want slave servers to initiate a zone transfer following either refresh SOA queries or NOTIFY messages from the master.
I've a BIND9 server with a lot of zones and I need to increase the serial number of the zone files by one.