Is it's own host name in the hosts file and nsswitch.conf set up correctly?

Alternatively disable all the ipv6 adapters if you aren't using them.

On Thu, May 24, 2012 at 12:23 PM, Tom Lloyd <> wrote:
> Say the webserver is called foo, on the domain company.local.  No ipv6 is 
> enabled in the network.  A network trace tells me that when the HTTP request 
> comes in, the webserver sends out a DNS request for "AAAA". 
>  Nothing replies, and after 5 seconds it times out and carries on doing what 
> it was doing.
> Why would it be doing a DNS lookup for the IPv6 address of its own hostname?  
> And more urgently, how can I stop it?
> -----Original Message-----
> From: Tom Lloyd
> Sent: 24 May 2012 16:26
> To: 'Matijn Woudt'
> Cc:
> Subject: RE: [PHP-DB] Mysterious 5 second delay on sybase_connect()
> I'm getting increasingly suspicious that DNS is to blame.  If I was to do 
> something like:
> $conn = sybase_connect( "\SQLMAIN", $user, $pass )
> Would that trigger a lookup of some variety?
> -----Original Message-----
> From: Matijn Woudt []
> Sent: 24 May 2012 13:00
> To: Tom Lloyd
> Cc:
> Subject: Re: [PHP-DB] Mysterious 5 second delay on sybase_connect()
> On Thu, May 24, 2012 at 10:51 AM, Tom Lloyd <> 
> wrote:
>> Hi there.  I'm working on a PHP-driven project on Debian Squeeze that
>> connects to an instance of Microsoft SQL Server on Windows Server 2008.
>> I'm using the sybase extensions to PHP.
>> Since I rebooted the webserver on the weekend, both the
>> sybase_connect() and sybase_pconnect() commands will sometimes take
>> exactly 5 seconds to execute.  It seems to be random whether they do
>> this or not.  I can't think of anything that could have been changed
>> by the reboot, unless a package was updated but its associated process never 
>> got restarted...
>> Does anyone know what might cause this behaviour?
>> Cheers,
>> Tom Lloyd
> It most likely has nothing to do with PHP, but is rather a routing issue. 5 
> seconds is the default connection time out for TCP/IP, so it probably makes 
> sense that the connection is failing at a lower level.
> - Matijn

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