Bug #53025 [Opn->Fbk]: checkdnsrr() result vary for specific server

Edit report at http://bugs.php.net/bug.php?id=53025&edit=1 ID: 53025 Updated by: pajoye@php.net Reported by: uni at daniel-marschall dot de Summary: checkdnsrr() result vary for specific server -Status: Open +Status: Feedback Type: Bug Package: Unknown/Other Function Operating System: Various PHP Version: Irrelevant Block user comment: N New Comment: I asked which OS and which versions of these OSes do you use. Please answer. Previous Comments: ------------------------------------------------------------------------ [2010-10-10 06:50:44] uni at daniel-marschall dot de Hello. I DO think that it is a bug in PHP. To your question, which OS I am using, please look in my initial comment again. I ran this testscript with wrong results on Windows AND Linux. It is not possible that my DNS/ISP is fault since I got also a Java application which checks A-records and there "us.ibm.com" has no A-records. But the PHP script says, A-records are available. ------------------------------------------------------------------------ [2010-10-09 01:50:43] pajoye@php.net Which operating system are you using exactly? Windows (which version?) Or linux? Windows has a different DNS implementation than unix. Also different results may be due to the use of different DNS servers. Be sure to check that every client uses the same. On windows you don't have to install PHP to test a new version but simply uncompress the zip somewhere and run: php -n dns.php from the php directory. ------------------------------------------------------------------------ [2010-10-09 00:46:39] uni at daniel-marschall dot de I have tried it now with PHP 5.3.3 at my Windows XP machine. Same result. A-record found. I expect that no A-record for this hostname is found. Alas, I cannot change the PHP versions for the 2 webservers. ------------------------------------------------------------------------ [2010-10-08 17:20:18] dominic at sayers dot cc Daniel - check http://bugs.php.net/bug.php?id=51844 I see you're using a mixture of PHP 5.2 and 5.3 - is this a new bug in 5.3 perhaps? ------------------------------------------------------------------------ [2010-10-08 16:20:39] uni at daniel-marschall dot de Description: ------------ I am trying to find out if a webserver has A-records or not. I found out that for the server "us.ibm.com" the results vary from client to client. Since I am writing an OpenSource application, I wish that the results of checkdnsrr() are consistent. I am not sure if it is a bug in PHP. Test script: --------------- <?php $phpver = phpversion(); echo "PHP version: $phpver<br>\r\n"; echo $_SERVER["SERVER_SIGNATURE"] . "<br>\r\n"; $server = 'us.ibm.com'; if (checkdnsrr($server, 'A')) { echo "$server A-record: VALID"; } else { echo "$server A-record: NOT VALID"; } ?> Expected result: ---------------- I do not know which result is correct. I checked the A-record at many different webservices and each webservice has different results. Example: * MX Toolbox: http://mxtoolbox.com/SuperTool.aspx?action=a%3aus.ibm.com (NO A-RECORD) * My-Addr.com: http://my-addr.com/domain-hostname-dns-records/isp-country-geo-ip-location/online-nslookup-tool/domain_info.php?domain=us.ibm.com&x=0&y=0 (A-RECORDS e32.co.us.ibm.com FOUND, but therefore no IP, so data MAY be incorrect) * OpenDNS also outputs some A-records for that domain, but I am not sure if they are valid * ntchosting.com: http://www.ntchosting.com/dns/host.html#Check_the_A_record - Various A-record FOUND! (e.g. e1.ny.us.ibm.com ) Actual result: -------------- Some PHP clients output "A record found", others output "No A record found". I do not know if it is controlled by the OS, the network or the PHP version. Examples for data I collected: 1. Tested at my Debian server (viathinksoft.de) and A-record FOUND. Software: Apache/2.2.9 (Debian) DAV/2 SVN/1.5.1 PHP/5.2.6-1+lenny8 with Suhosin-Patch mod_ssl/2.2.9 OpenSSL/0.9.8g mod_perl/2.0.4 Perl/v5.10.0 2. Tested at my XAMPP localhost with Windows XP Home and A-record FOUND. Software: Windows XP Home; XAMPP; Apache/2.2.14 (Win32) DAV/2 mod_ssl/2.2.14 OpenSSL/0.9.8l mod_autoindex_color PHP/5.3.1 mod_apreq2-20090110/2.7.1 mod_perl/2.0.4 Perl/v5.10.1 3. Tested at my university's server (jonathan.sv.hs-mannheim.de) and A-record NOT found. Software: Apache/2.2.8 (Fedora). PHP version: 5.2.6. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/bug.php?id=53025&edit=1