$sql_statement = qq|select str_ipaddress 
	from tbl_ipaddresses, tbl_names
	where tbl_names.str_name = 'firstname'
	and tbl_names.id_name = tbl_ipaddresses.id_name|;
$sth = $dbh->prepare($sql_statement);
$rv = $sth->execute;

while (	($ipaddress) = $sth->fetchrow_array ){
	# do whatever
}