Bind updating serial number for zones Adult chatroulette high qualitat
It uses a special format where the "@" character is replaced with a "." (period) character and the email address ends with a period. Serial number of the zone file that is incremented each time a change is made.
The secondary name servers compare the serial number returned by the primary name server with the serial number in their copy of the zone file to determine if they should update their zone file.
Perhaps it was too busy handling other requests just then.
The Retry Interval simply tells the secondary name server to wait for a period of time before trying again.
If the serial number from the primary name server is greater than their serial number, they will do a zone update transfer. If you make a change to the zone file on the primary name server and forget to increment the serial number, the change will not be propagated to the secondary name servers even if you attempt to force a zone update transfer.
The primary and secondary name servers will remain out of sync until the serial number is incremented on the primary name server.
Now if you control all of the authorative DNS servers for a domain (that is, the DNS servers that actually host the zone files and can answers queries for the domain as opposed to having to ask another DNS server), then with the exception of how long negative responses should be cached, these settings may not seem as important since you can force the secondary servers to update whenever needed.
By if you are using third-party name servers which you do not control as your secondary name servers (such as Peer 1's Super DNS servers), then these settings are vitally important to how fast any changes are propagated.
The value should not be so short that the primary name server is overwhelmed by update checks and not so long that propagation of changes to the secondary name servers are unduely delayed.If you control the secondary name servers and the zone file doesn't change that often, then you might want to set this to as long as day (86400 seconds), especially if you can force an update on the secondary name servers if needed.But if your secondary name servers are not under your control, then you'll probably want to set this to somewhere between 30 minutes (1800 seconds) and 2 hours (7200 seconds) to ensure any changes you make are propagated in a timely fashion.Even if you configure your primary name server to send NOTIFY messages (which I will cover in a future article) to the secondary name servers whenever a change is made, you should never completely depend on this to ensure timely propagation of the changes, especially when using third-party secondary name servers.The decision to honor a NOTIFY message is entirely up to the secondary name server and some DNS servers do not support NOTIFY.