One Domain; Multiple IPs.

[Joseph S D Yao]

On Mon, Jul 16, 2001 at 04:56:37PM -0400, Kevin Darcy wrote:
> Joseph S D Yao wrote:
> > You could have two name servers, giving out different IP addresses.
> > That way, if one side goes down, only HALF the accesses would be to the
> > dead IP address.
> 
> According to some interpretations, this is a DNS protocol violation. One
> could rationalize it as a very volatile data, but even in that case the
> protocol purists would insist that the SOA serial number be incremented
> every time the zone "changed", i.e. every time a different response was
> given by either nameserver.

Clarification: this was what Dominik was proposing, that name server A
always gave out IP address IP-A, and name server B always gave out IP
address IP-B.  There are a number of sites out there already doing this
for regional load balancing.  But when IP address IP-B is not working,
some have an internal protocol to switch to IP-A; others perhaps just
continue to fail until IP-B is working again.

No zone info changes at any one name server; not (I think) a protocol
violation.  Merely confusing.  ;-)

-- 
Joe Yao				jsdy at cospo.osis.gov - Joseph S. D. Yao
OSIS Center Computer Support					EMT-B
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