Hi, This is a DNS caching issue on the web server. Either the TTL on the DNS record needs to be shortened so it expires sooner or if you cannot wait for the that long you need a static IP to avoid DNS issues.
Sincerely, Mike -- Mike Brandonisio * Web Hosting Tech One Illustration * Internet Marketing tel (630) 759-9283 * e-Commerce [EMAIL PROTECTED] * http://www.jikometrix.net JIKOmetrix - Reliable web hosting On Mar 2, 2006, at 2:21 AM, riquez wrote: > Hi, > > For the purpose of security I would like to restrict access to our > web admin system to > users that are physically in our office. > To this end (& because our internet connection is always a dynamic > IP) I have registered a > dyndns.org domain & have software running to update our IP with the > dyndns servers. > > When a user logs in I can now compare their IP to the current IP of > our office. > > <?php > $officeIP = gethostbyname('example.dyndns.org'); > $userIP = $_SERVER['REMOTE_ADDR']; > ?> > > If they dont match, then I can reject the login. This seemed to > work fine for a short while, > but then after our IP changed it seems that the function > gethostbyname() is not > updating ... or is caching in PHP? > > I'm not sure which, but if I check my IP on whatismyip.com AND do a > Reverse DNS Lookup > on dnsstuff.com for <example.dyndns.org> - the IP's DO MATCH. > > PHP's gethostbyname() however reports the previous IP. If there was > a delay in PHP > updating I could understand, but it is always one step behind - > even if i force our office IP > to change, gethostbyname() quickly updates, but to the old IP - its > still one step behind. > > Can anyone help to explain this strange behaviour? > > Many Thanks, > Riquez > > > > > > > Community email addresses: > Post message: [email protected] > Subscribe: [EMAIL PROTECTED] > Unsubscribe: [EMAIL PROTECTED] > List owner: [EMAIL PROTECTED] > > Shortcut URL to this page: > http://groups.yahoo.com/group/php-list > Yahoo! Groups Links > > > > > > > > > Community email addresses: Post message: [email protected] Subscribe: [EMAIL PROTECTED] Unsubscribe: [EMAIL PROTECTED] List owner: [EMAIL PROTECTED] Shortcut URL to this page: http://groups.yahoo.com/group/php-list Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/php-list/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
