HSRP-like virtual DNS services.

[Barry Margolin]

In article <chkuq0$2etr$1 at sf1.isc.org>,
 Jonathan de Boyne Pollard <J.deBoynePollard at Tesco.NET> wrote:

> BM> [DNS Client libraries] typically allow you to specify multiple 
> nameservers,
> BM> but they often have a relatively long timeout (a few seconds) to switch
> BM> over to the backup server.  And they go through this timeout for
> BM> every query; [...]
> 
> Not all DNS Client libraries do that.  There is one particular DNS 
> Client library that, due to an implementation bug (since fixed, but with 
> the erroneous version still in widespread use), queries the alternate 
> proxy DNS server first for every subsequent query after it has once 
> timed out trying to query the preferred proxy DNS server.

I didn't say they all do that.  I was careful to qualify my response 
with "often", to indicate that this is common behavior, but not 
universal.  And unless you know that most of your clients have different 
behavior, you'd better design your caching DNS architecture to 
accomodate this type of client.

-- 
Barry Margolin, barmar at alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***