Bug #53025 [NEW]: checkdnsrr() result vary for specific server

From: Operating system: Various PHP version: Irrelevant Package: Unknown/Other Function Bug Type: Bug Bug description:checkdnsrr() result vary for specific server 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 bug report at http://bugs.php.net/bug.php?id=53025&edit=1 -- Try a snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=53025&r=trysnapshot52 Try a snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=53025&r=trysnapshot53 Try a snapshot (trunk): http://bugs.php.net/fix.php?id=53025&r=trysnapshottrunk Fixed in SVN: http://bugs.php.net/fix.php?id=53025&r=fixed Fixed in SVN and need be documented: http://bugs.php.net/fix.php?id=53025&r=needdocs Fixed in release: http://bugs.php.net/fix.php?id=53025&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=53025&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=53025&r=needscript Try newer version: http://bugs.php.net/fix.php?id=53025&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=53025&r=support Expected behavior: http://bugs.php.net/fix.php?id=53025&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=53025&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=53025&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=53025&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=53025&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=53025&r=dst IIS Stability: http://bugs.php.net/fix.php?id=53025&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=53025&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=53025&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=53025&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=53025&r=mysqlcfg