--- loncom/lond	2005/08/31 22:38:57	1.295
+++ loncom/lond	2005/09/01 07:49:43	1.296
@@ -2,7 +2,7 @@
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
 #
-# $Id: lond,v 1.295 2005/08/31 22:38:57 raeburn Exp $
+# $Id: lond,v 1.296 2005/09/01 07:49:43 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -59,7 +59,7 @@ my $DEBUG = 0;		       # Non zero to ena
 my $status='';
 my $lastlog='';
 
-my $VERSION='$Revision: 1.295 $'; #' stupid emacs
+my $VERSION='$Revision: 1.296 $'; #' stupid emacs
 my $remoteVERSION;
 my $currenthostid="default";
 my $currentdomainid;
@@ -4405,16 +4405,23 @@ sub ReadHostTable {
     open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab") || die "Can't read host file";
     my $myloncapaname = $perlvar{'lonHostID'};
     Debug("My loncapa name is : $myloncapaname");
+    my %name_to_ip;
     while (my $configline=<CONFIG>) {
 	if ($configline !~ /^\s*\#/ && $configline !~ /^\s*$/ ) {
 	    my ($id,$domain,$role,$name)=split(/:/,$configline);
 	    $name=~s/\s//g;
-	    my $ip = gethostbyname($name);
-	    if (length($ip) ne 4) {
-		&logthis("Skipping host $id name $name no IP $ip found\n");
-		next;
+	    my $ip;
+	    if (!exists($name_to_ip{$name})) {
+		$ip = gethostbyname($name);
+		if (!$ip || length($ip) ne 4) {
+		    &logthis("Skipping host $id name $name no IP found\n");
+		    next;
+		}
+		$ip=inet_ntoa($ip);
+		$name_to_ip{$name} = $ip;
+	    } else {
+		$ip = $name_to_ip{$name};
 	    }
-	    $ip=inet_ntoa($ip);
 	    $hostid{$ip}=$id;         # LonCAPA name of host by IP.
 	    $hostdom{$id}=$domain;    # LonCAPA domain name of host. 
 	    $hostip{$id}=$ip;         # IP address of host.