Simple DNS question about some basics. NOTIFY and REFRESH difference

[Kevin Darcy]

According to RFC 1996, all *registered* slaves are sent the NOTIFY.
*Stealth* slaves, however, i.e. ones not listed in the NS records for the
zone, do not get NOTIFYs by default, but you can use also-notify for them.
If a slave does not receive a NOTIFY, either because it was never sent, or
because the NOTIFY failed (probably due to some network problem), then it
will wait some period of time up to REFRESH since the last serial-number
check, before checking the zone, noticing that it has changed, and
replicating.

The bottom line is that if you want reasonably-fast propagation for a
stealth slave, make sure you have an also-notify for it.


- Kevin

Lists User wrote:

> When a master DNS is updated does it automatically NOTIFY the slave
> DNS?  Or must the slave dns go get a refresh when the SOA Refresh
> parameter has expired.

> If the Master does notify the Secondary (not waiting for the Slave record
> to expire) then does it do so by default?  I know you can specify
> additional nameservers you can have the master to notify, but by default
> it does all the ones listed as NS records.  Correct?
>
> Let me know how off I am here.
>
> Thanks,
> -Steve