Dynamic IP Address workaround

[Vitalik N.]

1. Yes, there is but it requires some scripting
2&3. I don't know any programs that do exactly what you want. So,
to get your external ip from NATed openbsd box you have to contact some
external web site (e.g: www.showmyip.com, showip.net and etc). my
favourite is checkip.dyndns.org since it retuns only one line (excluding
html header). Here is my implementation on perl: (getmyip.pl)

----------start--------------------------------------------------
#!/usr/bin/perl

use Socket;

$port = "80";
$host = "checkip.dyndns.org";

$iaddr=inet_aton($host);
$paddr=sockaddr_in($port,$iaddr);

socket(SOCK, PF_INET, SOCK_STREAM, getprotobyname('tcp'))
        or die "Couldn`t create socket : $!\n";

connect(SOCK, $paddr)
        or die "Couldn`t connect to $host:$port : $!\n";

send(SOCK, "GET / HTTP/1.1\nHost: checkip.dyndns.org\n\n", 0);

@data = <SOCK>;

$html = @data[8];
if($html =~ m/(\d+.?.\d+.?.\d+.?.\d+)/) {
        $myip = $1;
}
print("$myip\n");

close(SOCK);

-----------end--------------------------------------------------

Yes, you can use cron or you can modify the script above
so that it hangs in background and checks your ip after some
interval of time.