diff --git a/db/libdb.pm.in b/db/libdb.pm.in
index 5894a09ac9093e007b49c9551a6caaec9005a467..ae5caf9e2fbfa056e083c5905634010dec454150 100644
--- a/db/libdb.pm.in
+++ b/db/libdb.pm.in
@@ -87,7 +87,7 @@ use Exporter;
 	 TBDB_NODESTATE_ISUP TBDB_NODESTATE_REBOOTING TBDB_NODESTATE_REBOOTED
 	 TBDB_NODESTATE_SHUTDOWN TBDB_NODESTATE_BOOTING TBDB_NODESTATE_TBSETUP
 	 TBDB_NODESTATE_RELOADSETUP TBDB_NODESTATE_RELOADING
-	 TBDB_NODESTATE_RELOADDONE TBDB_NODESTATE_UNKNOWN
+	 TBDB_NODESTATE_RELOADDONE TBDB_NODESTATE_UNKNOWN TBDB_NODESTATE_PXEWAIT
 
 	 TBDB_NODEOPMODE_NORMAL TBDB_NODEOPMODE_DELAYING
 	 TBDB_NODEOPMODE_UNKNOWNOS TBDB_NODEOPMODE_RELOADING
@@ -167,6 +167,7 @@ use Exporter;
 	 TBSiteVarExists TBGetSiteVar
 
 	 TBActivityReport GatherSwapStats GatherAssignStats
+	 TBAvailablePCs
 
 	 TBDB_IFACEROLE_CONTROL TBDB_IFACEROLE_EXPERIMENT
 	 TBDB_IFACEROLE_JAIL TBDB_IFACEROLE_FAKE TBDB_IFACEROLE_OTHER
@@ -448,6 +449,7 @@ sub TBDB_NODESTATE_RELOADSETUP() { "RELOADSETUP"; }
 sub TBDB_NODESTATE_RELOADING()	{ "RELOADING"; }
 sub TBDB_NODESTATE_RELOADDONE()	{ "RELOADDONE"; }
 sub TBDB_NODESTATE_UNKNOWN()	{ "UNKNOWN"; };
+sub TBDB_NODESTATE_PXEWAIT()	{ "PXEWAIT"; }
 
 sub TBDB_NODEOPMODE_ANY		{ "*"; } # A wildcard opmode
 sub TBDB_NODEOPMODE_NORMAL	{ "NORMAL"; }
@@ -3430,6 +3432,35 @@ sub TBActivityReport($)
 			"where node_id='$node'");
 }
 
+#
+# Return the number of *available* nodes. These are nodes that are not
+# reserved and in the proper state. See corresponding code in ptopgen
+# and in the web server which reports the free node counts to users.
+#
+# usage: TBAvailablePCs(char *pid)
+#        Returns count.
+#
+sub TBAvailablePCs(;$)
+{
+    my ($pid) = @_;
+    my $clause = (defined($pid) ? "or p.pid='$pid'" : "");
+
+    my $query_result =
+	DBQueryFatal("select count(a.node_id) from nodes as a ".
+		     "left join reserved as b on a.node_id=b.node_id ".
+		     "left join node_types as nt on a.type=nt.type ".
+		     "left join nodetypeXpid_permissions as p ".
+		     "  on a.type=p.type ".
+		     "where b.node_id is null and a.role='testnode' and ".
+		     "      nt.class='pc' and ".
+                     "      (a.eventstate='" . TBDB_NODESTATE_ISUP . "' or ".
+                     "       a.eventstate='" . TBDB_NODESTATE_PXEWAIT . "') and".
+		     "      (p.pid is null $clause)");
+
+    my ($count) = $query_result->fetchrow_array();
+    return $count;
+}
+
 #
 # Gather Swap stats.
 #
diff --git a/tbsetup/assign_wrapper.in b/tbsetup/assign_wrapper.in
index 27c390cba64ec2491d6daf391dbfd9f6d7279174..0f4ddea2a8a88020d323cee9f18b773109b5a395 100644
--- a/tbsetup/assign_wrapper.in
+++ b/tbsetup/assign_wrapper.in
@@ -519,13 +519,7 @@ sub RunAssign ($)
     TBDebugTimeStamp("ptopgen finished");
 
     # Get number of nodes
-    my $numnodes_result = 
-	DBQueryFatal("select a.node_id,a.type from" .
-		     " nodes as a left join reserved as b" .
-		     " on a.node_id=b.node_id" .
-		     " where b.node_id is null" .
-		     " and a.role='testnode' and a.type!='dnard'");
-    $numnodes = $numnodes_result->numrows;
+    my $numnodes = TBAvailablePCs($pid);
     
     if ($numnodes < ($minimum_nodes - $reserved_pcount)) {
 	fatal($WRAPPER_FAILED|$WRAPPER_FAILED_CANRECOVER,
diff --git a/tbsetup/ptopgen.in b/tbsetup/ptopgen.in
index 4bdec54209f646e9ece2fef4ab64faf47792e832..61edb28838d774784a20727e7a7c9bcb9742eba1 100644
--- a/tbsetup/ptopgen.in
+++ b/tbsetup/ptopgen.in
@@ -212,7 +212,9 @@ else {
 #
 
 # the ordinary free condition for a local node.
-my $free_condition = "(b.node_id is null)";
+my $free_condition = "(b.node_id is null and ".
+                     " (np.eventstate='" . TBDB_NODESTATE_ISUP . "' or ".
+                     "  np.eventstate='" . TBDB_NODESTATE_PXEWAIT . "')) ";
 
 # if the user has specified an exempt pid/eid, 
 # then view any node which is reserved to that experiment as available.
@@ -226,6 +228,7 @@ $result =
 		 "from nodes as a ".
 		 "left join reserved as b on a.node_id=b.node_id ".
 		 "left join reserved as m on a.phys_nodeid=m.node_id ".
+		 "left join nodes as np on a.phys_nodeid=np.node_id ".
 		 "left join node_types as t on t.type=a.type ".
 		 "where $free_condition and ".
 		 "      (a.role='testnode' and t.isremotenode=0)");
diff --git a/www/dbdefs.php3.in b/www/dbdefs.php3.in
index eec19b2a630a74aeeb1ad1c22e21538cefbaa03f..4d58eb5efea9ce06e49aa85b2cd7211d10ff129b 100644
--- a/www/dbdefs.php3.in
+++ b/www/dbdefs.php3.in
@@ -138,6 +138,10 @@ define("TBDB_IFACEROLE_FAKE",		"fake");
 define("TBDB_IFACEROLE_GW",		"gw");
 define("TBDB_IFACEROLE_OTHER",		"other");
 
+# Node states that the web page cares about.
+define("TBDB_NODESTATE_ISUP",		"ISUP");
+define("TBDB_NODESTATE_PXEWAIT",	"PXEWAIT");
+
 # User Interface types
 define("TBDB_USER_INTERFACE_EMULAB",	"emulab");
 define("TBDB_USER_INTERFACE_PLAB",	"plab");
@@ -1409,22 +1413,34 @@ function TBExpUidLastLogins($pid, $eid)
 }
 
 #
-# Number of globally free PCs.
+# Number of globally free PCs. See ptopgen and libdb for corresponding
+# usage of the eventstate. A node is not really considered free for use
+# unless it is also in the ISUP/PXEWAIT state.
 #
 function TBFreePCs()
 {
     $query_result =
-	DBQueryFatal("select a.node_id from nodes as a ".
+	DBQueryFatal("select count(a.node_id) from nodes as a ".
 		     "left join reserved as b on a.node_id=b.node_id ".
 		     "left join node_types as nt on a.type=nt.type ".
 		     "left join nodetypeXpid_permissions as p ".
 		     "  on a.type=p.type ".
 		     "where b.node_id is null and a.role='testnode' ".
-		     "  and nt.class = 'pc' and p.pid is null");
-
-    return mysql_num_rows($query_result);
+		     "  and nt.class = 'pc' and p.pid is null and ".
+                     "      (a.eventstate='" . TBDB_NODESTATE_ISUP . "' or ".
+                     "       a.eventstate='" . TBDB_NODESTATE_PXEWAIT . "') and".
+		     "      (p.pid is null)");
+    
+    if (mysql_num_rows($query_result) == 0) {
+	return 0;
+    }
+    $row = mysql_fetch_row($query_result);
+    return $row[0];
 }
 
+#
+# Number of PCs a user has reserved to his experiments.
+#
 function TBUserPCs($uid)
 {
     $query_result =