order of address-records

[Barry Margolin]

In article <92fnea$s9a at pub3.rc.vix.com>,
Stephan M. Ott <nsmo at okdesign.de> wrote:
>I entered two different address-records for a domins in BIND8. Works fine;
>when looking up this domain I get two answers. This means, when one of the
>servers is not available, the other one will be taken, right ?

That depends on the application.  Many only use the first address, some
will try them all.

>Okay, when now a browser asks for this domain, he will also get this two
>answers (won't he ?)

Depends on what the browser programmer decided to do.

>Which one will he choose for connecting ? The first one, the second one, or
>is this decision made by random ?

Probably the first one in the response he got.

>In case he will take the first (or last) one, how can I influence which one
>he will take ?

You can't easily do this just with DNS.  His local DNS server most likely
has round-robin enabled, so you don't have any control over the order.

>The "main" server should be taken first, and only if this one is not
>reachable (or the net-route to this server is overloaded) the other server
>should be taken.
>Any ideas ?

Use something like Cisco Distributed Director.  Hardware and software
products like this monitor the servers and only give out the address of a
server that's up.

-- 
Barry Margolin, barmar at genuity.net
Genuity, Burlington, MA
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