--- loncom/auth/migrateuser.pm	2014/10/04 02:59:32	1.21
+++ loncom/auth/migrateuser.pm	2014/10/05 13:49:11	1.22
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Starts a user off based of an existing token.
 #
-# $Id: migrateuser.pm,v 1.21 2014/10/04 02:59:32 raeburn Exp $
+# $Id: migrateuser.pm,v 1.22 2014/10/05 13:49:11 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -72,23 +72,26 @@ sub ip_changed {
     if (ref($dataref) eq 'HASH') {
         my $title = 'LON-CAPA Session redirected';
         my $message = &mt('Your internet address has changed since you logged in.');  
-        my $camefrom = &Apache::lonnet::hostname($dataref->{'server'});
-        my $frombalancer = $dataref->{'balancer'};
         my $rule_in_effect;
-        if ($frombalancer) {
-            my $balancerdom = &Apache::lonnet::host_domain($dataref->{'server'});
-            if ($dataref->{'sso.login'}) {
-                if (&Apache::lonnet::domain($dataref->{'domain'})) {
-                    $balancerdom = $dataref->{'domain'};
-                }
+        if ($dataref->{'balancer'}) {
+            my $baldom = &Apache::lonnet::host_domain($camefrom);
+            my $balprimaryid = &Apache::lonnet::domain($baldom,'primary');
+            my $balintdom = &Apache::lonnet::internet_dom($balprimaryid);
+            my $uprimaryid = &Apache::lonnet::domain($udom,'primary'); 
+            my $uintdom = &Apache::lonnet::internet_dom($uprimaryid);
+            my $dom_in_use;
+            if (($uintdom ne '') && ($uintdom eq $balintdom)) {
+                $dom_in_use = $udom;
+            } else {
+                $dom_in_use = $baldom;
             }
-            my ($result,$cached)=&Apache::lonnet::is_cached_new('loadbalancing',$balancerdom);
+            my ($result,$cached)=&Apache::lonnet::is_cached_new('loadbalancing',$dom_in_use);
             unless (defined($cached)) {
                 my $cachetime = 60*60*24; 
                 my %domconfig =
-                    &Apache::lonnet::get_dom('configuration',['loadbalancing'],$balancerdom);
+                    &Apache::lonnet::get_dom('configuration',['loadbalancing'],$dom_in_use);
                 if (ref($domconfig{'loadbalancing'}) eq 'HASH') {
-                    $result = &Apache::lonnet::do_cache_new('loadbalancing',$balancerdom,
+                    $result = &Apache::lonnet::do_cache_new('loadbalancing',$dom_in_use,
                                                             $domconfig{'loadbalancing'},$cachetime);
                 }
             }