--- loncom/lonnet/perl/lonnet.pm	2007/06/13 01:43:54	1.888
+++ loncom/lonnet/perl/lonnet.pm	2007/06/25 23:31:33	1.890.2.2
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.888 2007/06/13 01:43:54 albertel Exp $
+# $Id: lonnet.pm,v 1.890.2.2 2007/06/25 23:31:33 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -149,7 +149,7 @@ sub create_connection {
 				     Type    => SOCK_STREAM,
 				     Timeout => 10);
     return 0 if (!$client);
-    print $client (join(':',$hostname,$lonid,&machine_ids($lonid))."\n");
+    print $client (join(':',$hostname,$lonid,&machine_ids($hostname))."\n");
     my $result = <$client>;
     chomp($result);
     return 1 if ($result eq 'done');
@@ -7601,7 +7601,10 @@ sub machine_ids {
     $hostname ||= &hostname($perlvar{'lonHostID'});
     my @ids;
     my %name_to_host = &all_names();
-    return @{ $name_to_host{$hostname} };
+    if (ref($name_to_host{$hostname}) eq 'ARRAY') {
+	return @{ $name_to_host{$hostname} };
+    }
+    return;
 }
 
 sub additional_machine_domains {
@@ -7714,7 +7717,6 @@ sub correct_line_ends {
 
 sub goodbye {
    &logthis("Starting Shut down");
-		    &logthis("test");
 #not converted to using infrastruture and probably shouldn't be
    &logthis(sprintf("%-20s is %s",'%badServerCache',length(&nfreeze(\%badServerCache))));
 #converted
@@ -7852,6 +7854,7 @@ sub get_dns {
     sub reset_hosts_info {
 	&reset_domain_info();
 	&reset_hosts_ip_info();
+	undef(%name_to_host);
 	undef(%hostname);
 	undef(%hostdom);
 	undef(%libserv);
@@ -7943,24 +7946,6 @@ sub get_dns {
     my %name_to_ip;
     my %lonid_to_ip;
 
-    my %valid_ip;
-    sub valid_ip {
-	my ($ip) = @_;
-	if (exists($iphost{$ip}) || exists($valid_ip{$ip})) {
-	    return 1;	
-	}
-	my $name = gethostbyip($ip);
-	my $lonid = &hostname($name);
-	if (defined($lonid)) {
-	    $valid_ip{$ip} = $lonid;
-	    return 1;
-	}
-	my %iphosts = &get_iphost();
-	if (ref($iphost{$ip})) {
-	    return 1;	
-	}
-    }
-
     sub get_hosts_from_ip {
 	my ($ip) = @_;
 	my %iphosts = &get_iphost();
@@ -7992,6 +7977,7 @@ sub get_dns {
     
     sub get_iphost {
 	my ($ignore_cache) = @_;
+
 	if (!$ignore_cache) {
 	    if (%iphost) {
 		return %iphost;
@@ -8005,16 +7991,31 @@ sub get_dns {
 		return %iphost;
 	    }
 	}
+
+	# get yesterday's info for fallback
+	my %old_name_to_ip;
+	my ($ip_info,$cached)=
+	    &Apache::lonnet::is_cached_new('iphost','iphost');
+	if ($cached) {
+	    %old_name_to_ip = %{$ip_info->[1]};
+	}
+
 	my %name_to_host = &all_names();
 	foreach my $name (keys(%name_to_host)) {
 	    my $ip;
 	    if (!exists($name_to_ip{$name})) {
 		$ip = gethostbyname($name);
 		if (!$ip || length($ip) ne 4) {
-		    &logthis("Skipping name $name no IP found");
-		    next;
+		    if (defined($old_name_to_ip{$name})) {
+			$ip = $old_name_to_ip{$name};
+			&logthis("Can't find $name defaulting to old $ip");
+		    } else {
+			&logthis("Name $name no IP found");
+			next;
+		    }
+		} else {
+		    $ip=inet_ntoa($ip);
 		}
-		$ip=inet_ntoa($ip);
 		$name_to_ip{$name} = $ip;
 	    } else {
 		$ip = $name_to_ip{$name};
@@ -8026,7 +8027,7 @@ sub get_dns {
 	}
 	&Apache::lonnet::do_cache_new('iphost','iphost',
 				      [\%iphost,\%name_to_ip,\%lonid_to_ip],
-				      24*60*60);
+				      48*60*60);
 
 	return %iphost;
     }