Turning on a secondary Interface

Barry Margolin barmar at genuity.net
Mon Jan 7 22:49:25 UTC 2002


In article <a1cuj8$5av at pub3.rc.vix.com>,
Martin G. McCormick <martin at dc.cis.okstate.edu> wrote:
>	If a system running bind-9 has a second Ethernet
>interface and that port is enabled, will named answer queries on
>both interfaces?

Yes.  If the "listen-on" option isn't included in the named.conf, the
default is to listen on all interfaces.

>	The idea is to configure the secondary interface on our
>slave dns to have the network address of the master so that if
>the master failed, the systems on our campus would still get to
>talk to a dns on the primary or master address and not have to
>fail over to the secondary.
>
>	When the master was back in working order, the secondary
>interface on the slave would be turned back off again so I am
>asking whether this occasional operation will cause any
>unexpected surprises?

I think this should work.  Note, however, that named will not start
listening on the secondary address immediately.  It periodically scans the
interface configuration to see if any addresses have come or gone, and
updates the addresses it's listening on to match; the default period of
this is hourly, and you can change it with the "interface-interval"
option.  I suppose that whenever you reconfigure the backup server to have
the secondary address, you could also restart named so that it will
immediately start listening.

-- 
Barry Margolin, barmar at genuity.net
Genuity, Woburn, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.


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