conflicting gethostbyname behaviors

[yawnmoth]

I seem to be getting conflicting gethostbyname behavior on different
servers. Before going into detail, here's the script I'm using:

<?
$address = $HTTP_SERVER_VA RS['REMOTE_ADDR'];
$rev = implode('.',arr ay_reverse(expl ode('.', $address)));

$lookup = "$rev.l1.spews. dnsbl.sorbs.net ";
echo gethostbyname($ lookup);
echo '<br />';
echo $lookup;
?>

On server A, the output I get is as follows:

176.115.112.70. l1.spews.dnsbl. sorbs.net
176.115.112.70. l1.spews.dnsbl. sorbs.net

On server B, the output I get is this:

195.69.95.204
176.115.112.70. l1.spews.dnsbl. sorbs.net

As I understand it, server A's output is the correct output - not
server B's.

Server A is running PHP Version 4.4.1 with Apache/1.3.34 while server B
is running PHP Version 4.3.11 with Apache/2.0.52. I'd like the above
script, however, to work just as well on server A as it does on server
B.

Any ideas as to how I might go about doing this or what the problem is?
Any help would be appreciated - thanks!

[Erwin Moller]

Re: conflicting gethostbyname behaviors

yawnmoth wrote:
[color=blue]
> I seem to be getting conflicting gethostbyname behavior on different
> servers. Before going into detail, here's the script I'm using:
>
> <?
> $address = $HTTP_SERVER_VA RS['REMOTE_ADDR'];
> $rev = implode('.',arr ay_reverse(expl ode('.', $address)));
>
> $lookup = "$rev.l1.spews. dnsbl.sorbs.net ";
> echo gethostbyname($ lookup);
> echo '<br />';
> echo $lookup;
> ?>
>
> On server A, the output I get is as follows:
>
> 176.115.112.70. l1.spews.dnsbl. sorbs.net
> 176.115.112.70. l1.spews.dnsbl. sorbs.net
>
> On server B, the output I get is this:
>
> 195.69.95.204
> 176.115.112.70. l1.spews.dnsbl. sorbs.net
>
> As I understand it, server A's output is the correct output - not
> server B's.
>
> Server A is running PHP Version 4.4.1 with Apache/1.3.34 while server B
> is running PHP Version 4.3.11 with Apache/2.0.52. I'd like the above
> script, however, to work just as well on server A as it does on server
> B.
>
> Any ideas as to how I might go about doing this or what the problem is?
> Any help would be appreciated - thanks![/color]

Hi,

Did one of them change recently their name maybe?
PHP caches lookups. (Or rather Apache does if I understand it well).

What MIGHT help are some usercontributed notes on www.php.net:

Two possibilities:
1) restart Apache (in case of caching DNS-problem)
2) Do not use gethostbyname, but use 'dig' instead.

Just go to www.php.net and look up the function for details.

Regards,
Erwin Moller