The best method would be to ask your hosting provider, but if you have SSH access you could do a simple ping, curl or even traceroute. If you do not have SSH access then you may be able to run this PHP script:
SOURCE
if (!$file) $status = -1; // Site is down
else {
fclose($file);
$status = ($stoptime - $starttime) * 1000;
$status = floor($status);
}
return $status; } ?>
<DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "DTD/xhtml1-transitional.dtd"> <html> <body>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post" name="domain">
Domain name:
<table>
<input name="domainname" type="text" >
<input type="submit" name="submitBtn" value="Ping domain">
</table>
</form> <?php
// Check whether the for was submitted
if (isset($_POST['submitBtn'])){
$domainbase = (isset($_POST['domainname'])) ? $_POST['domainname'] : '';
$domainbase = str_replace("http://","",strtolower($domainbase));
echo '<table>';
$status = pingDomain($domainbase);
if ($status != -1) echo "<tr><td>http://$domainbase is ALIVE ($status ms)</td><tr>";
else echo "<tr><td>http://$domainbase is DOWN</td><tr>";
echo '</table>';
} ?> </body> </html>