fsockopen() error : Network is unreachable port 43 in php

Question

i've writed some Php code that lookup for domain (whois) but it fails !!

this is some of my code :

function checkdomain($server,$domain){
global $response;
    $connection = fsockopen($server,43);
    fputs($connection, "domain " . $domain . "\r\n");
    while(!feof($connection)){
        $response .= fgets($connection, 4096);
    }
    fclose($connection);
}
checkdomain("whois.crsnic.net","www.example.com");

the code work on my localhost ( apache,php,mysql, OS -> Win XP ) but when i uploaded it to my host (Linux) it failed. and i always see the Below Error/message :

Warning: fsockopen() [function.fsockopen]: unable to connect to whois.crsnic.net:43 
(Network is unreachable) in /home/hamid0011/public_html/whois/whois.php on line 37

what should i do ? is this my host's problem or whois server ( but it work in localhost ) or my code?

Answer 1

Either your host has blocked outgoing communications on port 43, or the shared server IP you're using has hit the WHOIS server so hard that they've resorted to blocking your IP (not very likely).

In any case, you'll need to contact your host.

Obtaining a traceroute whois.crsnic.net might be useful, if you have shell access. If you can paste one here, we might also be able to debug your issue better (the outputs of the whois command and the telnet one would also be useful as SvenW has said).