MX freebsd

[Greg Maruszeczka]

Glenn Dawson wrote:
> At 04:53 PM 11/25/2005, Beecher Rintoul wrote:
> 
>> On Friday 25 November 2005 03:43 pm, Francisco Reyes wrote:
>> > dick hoogendijk writes:
>> > > Any idea how long it takes until the MX freebsd mailservers know that
>> > > my mail relay has changed? It's three days ago now that I changed
>> my MX
>> > > records and still mail for nagual.st is routed to my old mx
>> > > mailservers.
>> > >
>> > >dig nagual.st mx
>> >
>> > ;;; QUESTION SECTION:
>> > ;nagual.st.                     IN      MX
>> >
>> > ;; ANSWER SECTION:
>> > nagual.st.              86400   IN      MX      10 mx1.mailhop.org.
>> > nagual.st.              86400   IN      MX      20 mx2.mailhop.org.
>> >
>> > >bc
>> >
>> > 86400/3600
>> > 24
>> >
>> >
>> > Should only take a day based on the results above.
>> >
>> > The command to see your XM settings is
>> > dig <url> mx
>>
>> Did you update the serial number when you changed the MX record?
>> Servers downline will not see the changes otherwise.
> 
> 
> Actually, the serial number is only used by the slave servers for a
> particular zone to decide whether or not a zone transfer is needed.
> 

I don't think that's entirely true. The serial number is also used by
named internally to determine whether to reload your zones, and hence,
to make the actual change in memory. AFAIK if you don't update the
serial number the change won't take effect.

To confirm this I just ran `rndc reload` and then checked
/var/log/messages on my closest available OBSD name server. Reloaded
named.conf but NOT my zone files. Then I changed the serial on one of my
primary zone files and ran `rndc reload` again. This time syslog records
that both named.conf and that zone have been reloaded.

Of course, the serial number change ALSO signals to slaves that they
need to update their copies.