Check an IP-Adress

[Anon]

Hello,
how can I check if an IP-Adress is already exists?

1. I get the IP-Adress
2. Later I want to check if the IP-Adress is online

[Anon]

<?

$phpc = fsockopen("ipaddr", 80, &$errno, &$errstr, 30);

if(!$phpc)
{

echo "<b>ip <font color=red>down!!</font></b>\n";
}

else
{

echo("<a href=http://ipaddr>ipaddr</a>");

}

?>

try this..it mite work

[[deleted]]

but it won't.

This only checks if there is a service responding on port 80. DNS servers will never respond on port 80.

If you want to know if the server is reachable, use PING.

[Anon]

Hello,
thank you for the answer.

But i don't want to check a Server.
I want to check the User.

1. If the user connect to out Internet-Page
   i get the ip with $REMOTE_ADDR

2. After some Minutes i want to check

   • is the User already online?

[[deleted]]

So you want to check if some user is visiting your website?

[Anon]

If the user is behind a firewall, they may not even be pingable. Using sessions that time out is the only way I can see of deciding if someone is online.

[[deleted]]

I posted that before Lutze mentioned he was talking about users.

[Anon]

theres no way of doing this ip-checking if user is

i) behind a firewall (almost all corporate/ business users)

ii) using a proxy server (most people using freeserve in uk - dont know about other countries)

sorry to be a spoiler 🙁