Date: Sun, 23 Apr 2000 21:42:53 +0200 From: sthaug@nethelp.no To: james@targetnet.com Cc: leifn@neland.dk, yurtesen@dc.ispro.net, freebsd-hackers@FreeBSD.ORG Subject: Re: bind and the limit of serial number ??? Message-ID: <58853.956518973@verdi.nethelp.no> In-Reply-To: Your message of "Sun, 23 Apr 2000 14:32:24 -0400" References: <20000423143224.C26932@targetnet.com>
next in thread | previous in thread | raw e-mail | index | archive | help
> > I once put in an extra digit in the serial number. > > This made a secondary use a serial number, which was larger than mine, and > > could probably be the modulus 2^32. > > I had to call the hostmaster there (A "3.rd secondary" hosted at our > > uplink) to get the zonefile removed, so the right one would be reloaded. > > Just FYI: if you make the serial number of a zone '0', secondary servers > (bind at least) will *always* grab the zone from the master. It's intended > to fix just the situation you had; set the serial to 0, leave it that way > until all the slaves have picked up the new zone, then start using the > proper numbering scheme again. It wastes bandwidth for a while if you have > a large number of secondaries and/or a low refresh time, but it lets you fix > a type without human intervention. This is a BIND feature, and should not be relied on. From RFC 1982: Caution should also be exercised before causing the serial number to be set to the value zero. While this value is not in any way special in serial number arithmetic, or to the DNS SOA serial number, many DNS implementations have incorrectly treated zero as a special case, with special properties, and unusual behaviour may be expected if zero is used as a DNS SOA serial number. There are better methods if you need to lower the serial number. The standard method, which is guaranteed to work, is to increase the serial number by 2^31-1 on the primary (largest increase allowed by serial number arithmetic, se RFC 1982), wait one refresh period (then the slave will have picked up the new serial number), and *then* set it to the desired value. Steinar Haug, Nethelp consulting, sthaug@nethelp.no To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?58853.956518973>