--- loncom/lonnet/perl/londns.pm	2018/07/18 13:45:03	1.5
+++ loncom/lonnet/perl/londns.pm	2018/07/30 14:39:51	1.6
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # A debugging harness.
 #
-# $Id: londns.pm,v 1.5 2018/07/18 13:45:03 raeburn Exp $
+# $Id: londns.pm,v 1.6 2018/07/30 14:39:51 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -31,7 +31,7 @@ package Apache::londns;
 
 use strict;
 use LONCAPA;
-use Apache::Constants qw(:common :http);
+use Apache::Constants qw(:common :http :remotehost);
 use Apache::lonnet;
 
 sub serve_file {
@@ -54,6 +54,14 @@ sub serve_file {
 sub handler {
     my ($r) = @_;
 
+    my $reqhost = $r->get_remote_host(REMOTE_NOLOOKUP);
+    my @hostids= &Apache::lonnet::get_hosts_from_ip($reqhost);
+    if (!@hostids && $reqhost ne '127.0.0.1' ) {
+        $r->log_reason("Unable to find a host for ".
+                       $r->get_remote_host(REMOTE_NOLOOKUP));
+        return FORBIDDEN;
+    }
+
     my $command = (split('/',$r->uri))[3];
     my $dir = $Apache::lonnet::perlvar{'lonTabDir'};
     if ($command eq 'hosts') {