diff --git a/orte/mca/plm/base/plm_base_launch_support.c b/orte/mca/plm/base/plm_base_launch_support.c
index a178f42e84..1a5d6e594c 100644
--- a/orte/mca/plm/base/plm_base_launch_support.c
+++ b/orte/mca/plm/base/plm_base_launch_support.c
@@ -1714,7 +1714,7 @@ int orte_plm_base_setup_virtual_machine(orte_job_t *jdata)
                 OPAL_OUTPUT_VERBOSE((5, orte_plm_base_framework.framework_output,
                                      "%s using dash_host",
                                      ORTE_NAME_PRINT(ORTE_PROC_MY_NAME)));
-                if (ORTE_SUCCESS != (rc = orte_util_add_dash_host_nodes(&tnodes, hosts))) {
+                if (ORTE_SUCCESS != (rc = orte_util_add_dash_host_nodes(&tnodes, hosts, false))) {
                     ORTE_ERROR_LOG(rc);
                     free(hosts);
                     return rc;
diff --git a/orte/mca/ras/base/ras_base_allocate.c b/orte/mca/ras/base/ras_base_allocate.c
index 353d1236f5..60212a4227 100644
--- a/orte/mca/ras/base/ras_base_allocate.c
+++ b/orte/mca/ras/base/ras_base_allocate.c
@@ -312,7 +312,7 @@ void orte_ras_base_allocate(int fd, short args, void *cbdata)
             OPAL_OUTPUT_VERBOSE((5, orte_ras_base_framework.framework_output,
                                  "%s ras:base:allocate adding dash_hosts",
                                  ORTE_NAME_PRINT(ORTE_PROC_MY_NAME)));
-            if (ORTE_SUCCESS != (rc = orte_util_add_dash_host_nodes(&nodes, hosts))) {
+            if (ORTE_SUCCESS != (rc = orte_util_add_dash_host_nodes(&nodes, hosts, true))) {
                 free(hosts);
                 OBJ_DESTRUCT(&nodes);
                 ORTE_FORCED_TERMINATE(ORTE_ERROR_DEFAULT_EXIT_CODE);
@@ -511,7 +511,7 @@ int orte_ras_base_add_hosts(orte_job_t *jdata)
             opal_output_verbose(5, orte_ras_base_framework.framework_output,
                                 "%s ras:base:add_hosts checking add-host %s",
                                 ORTE_NAME_PRINT(ORTE_PROC_MY_NAME), hosts);
-            if (ORTE_SUCCESS != (rc = orte_util_add_dash_host_nodes(&nodes, hosts))) {
+            if (ORTE_SUCCESS != (rc = orte_util_add_dash_host_nodes(&nodes, hosts, true))) {
                 ORTE_ERROR_LOG(rc);
                 OBJ_DESTRUCT(&nodes);
                 free(hosts);
diff --git a/orte/mca/rmaps/base/rmaps_base_support_fns.c b/orte/mca/rmaps/base/rmaps_base_support_fns.c
index 6711643e35..5c41004541 100644
--- a/orte/mca/rmaps/base/rmaps_base_support_fns.c
+++ b/orte/mca/rmaps/base/rmaps_base_support_fns.c
@@ -171,7 +171,7 @@ int orte_rmaps_base_get_target_nodes(opal_list_t *allocated_nodes, orte_std_cntr
             OPAL_OUTPUT_VERBOSE((5, orte_rmaps_base_framework.framework_output,
                                  "%s using dash_host %s",
                                  ORTE_NAME_PRINT(ORTE_PROC_MY_NAME), hosts));
-            if (ORTE_SUCCESS != (rc = orte_util_add_dash_host_nodes(&nodes, hosts))) {
+            if (ORTE_SUCCESS != (rc = orte_util_add_dash_host_nodes(&nodes, hosts, false))) {
                 ORTE_ERROR_LOG(rc);
                 free(hosts);
                 return rc;
diff --git a/orte/runtime/orte_globals.c b/orte/runtime/orte_globals.c
index c4efb64987..e244cf64bf 100644
--- a/orte/runtime/orte_globals.c
+++ b/orte/runtime/orte_globals.c
@@ -155,6 +155,7 @@ bool orte_default_hostfile_given = false;
 char *orte_rankfile = NULL;
 int orte_num_allocated_nodes = 0;
 char *orte_node_regex = NULL;
+char *orte_default_dash_host = NULL;
 
 /* tool communication controls */
 bool orte_report_events = false;
diff --git a/orte/runtime/orte_globals.h b/orte/runtime/orte_globals.h
index cda7d7db65..bfa4cd63af 100644
--- a/orte/runtime/orte_globals.h
+++ b/orte/runtime/orte_globals.h
@@ -540,6 +540,7 @@ ORTE_DECLSPEC extern bool orte_default_hostfile_given;
 ORTE_DECLSPEC extern char *orte_rankfile;
 ORTE_DECLSPEC extern int orte_num_allocated_nodes;
 ORTE_DECLSPEC extern char *orte_node_regex;
+ORTE_DECLSPEC extern char *orte_default_dash_host;
 
 /* PMI version control */
 ORTE_DECLSPEC extern int orted_pmi_version;
diff --git a/orte/runtime/orte_mca_params.c b/orte/runtime/orte_mca_params.c
index accf21eebf..a469d9c361 100644
--- a/orte/runtime/orte_mca_params.c
+++ b/orte/runtime/orte_mca_params.c
@@ -362,6 +362,14 @@ int orte_register_params(void)
         orte_default_hostfile_given = true;
     }
 
+    /* default dash-host */
+    orte_default_dash_host = NULL;
+    (void) mca_base_var_register ("orte", "orte", NULL, "default_dash_host",
+                                  "Default -host setting, \"none\" to ignore environmental or default MCA param setting)",
+                                  MCA_BASE_VAR_TYPE_STRING, NULL, 0, 0,
+                                  OPAL_INFO_LVL_9, MCA_BASE_VAR_SCOPE_READONLY,
+                                  &orte_default_dash_host);
+
     /* regex of nodes in system */
     orte_node_regex = NULL;
     (void) mca_base_var_register ("orte", "orte", NULL, "node_regex",
diff --git a/orte/tools/orte-submit/orte-submit.c b/orte/tools/orte-submit/orte-submit.c
index 23656b08d5..35f3dc61af 100644
--- a/orte/tools/orte-submit/orte-submit.c
+++ b/orte/tools/orte-submit/orte-submit.c
@@ -1169,6 +1169,9 @@ static int create_app(int argc, char* argv[],
         orte_set_attribute(&app->attributes, ORTE_APP_DASH_HOST, ORTE_ATTR_GLOBAL, tval, OPAL_STRING);
         opal_argv_free(targ);
         free(tval);
+    } else if (NULL != orte_default_dash_host) {
+        orte_set_attribute(&app->attributes, ORTE_APP_DASH_HOST, ORTE_ATTR_LOCAL,
+                           orte_default_dash_host, OPAL_STRING);
     }
 
     /* check for bozo error */
diff --git a/orte/tools/orterun/orterun.c b/orte/tools/orterun/orterun.c
index 023cdea8ab..8c7acc5e7e 100644
--- a/orte/tools/orterun/orterun.c
+++ b/orte/tools/orterun/orterun.c
@@ -1586,6 +1586,9 @@ static int create_app(int argc, char* argv[],
         orte_set_attribute(&app->attributes, ORTE_APP_DASH_HOST, ORTE_ATTR_LOCAL, tval, OPAL_STRING);
         opal_argv_free(targ);
         free(tval);
+    } else if (NULL != orte_default_dash_host) {
+        orte_set_attribute(&app->attributes, ORTE_APP_DASH_HOST, ORTE_ATTR_LOCAL,
+                           orte_default_dash_host, OPAL_STRING);
     }
 
     /* check for bozo error */
diff --git a/orte/util/dash_host/dash_host.c b/orte/util/dash_host/dash_host.c
index f5d7a83683..edd71ef5d9 100644
--- a/orte/util/dash_host/dash_host.c
+++ b/orte/util/dash_host/dash_host.c
@@ -44,11 +44,11 @@
  * relative node syntax should generate an immediate error
  */
 int orte_util_add_dash_host_nodes(opal_list_t *nodes,
-                                  char *hosts)
+                                  char *hosts, bool allocating)
 {
     opal_list_item_t *item, *itm;
     orte_std_cntr_t i, j, k;
-    int rc;
+    int rc, nodeidx;
     char **host_argv=NULL;
     char **mapped_nodes = NULL, **mini_map, *ndname;
     orte_node_t *node, *nd;
@@ -59,8 +59,8 @@ int orte_util_add_dash_host_nodes(opal_list_t *nodes,
     char *cptr;
 
     OPAL_OUTPUT_VERBOSE((1, orte_ras_base_framework.framework_output,
-                         "%s dashhost: parsing args",
-                         ORTE_NAME_PRINT(ORTE_PROC_MY_NAME)));
+                         "%s dashhost: parsing args %s",
+                         ORTE_NAME_PRINT(ORTE_PROC_MY_NAME), hosts));
 
     OBJ_CONSTRUCT(&adds, opal_list_t);
     host_argv = opal_argv_split(hosts, ',');
@@ -85,6 +85,7 @@ int orte_util_add_dash_host_nodes(opal_list_t *nodes,
         }
     }
     opal_argv_free(host_argv);
+    mini_map = NULL;
 
     /* Did we find anything? If not, then do nothing */
     if (NULL == mapped_nodes) {
@@ -92,23 +93,96 @@ int orte_util_add_dash_host_nodes(opal_list_t *nodes,
         goto cleanup;
     }
 
+    for (i = 0; NULL != mapped_nodes[i]; ++i) {
+        /* if the specified node contains a relative node syntax,
+         * and we are allocating, then ignore it
+         */
+        if ('+' == mapped_nodes[i][0]) {
+            if (!allocating) {
+                if ('e' == mapped_nodes[i][1] ||
+                    'E' == mapped_nodes[i][1]) {
+                    /* request for empty nodes - do they want
+                     * all of them?
+                     */
+                    if (NULL != (cptr = strchr(mapped_nodes[i], ':'))) {
+                        /* the colon indicates a specific # are requested */
+                        ++cptr;
+                        j = strtoul(cptr, NULL, 10);
+                    } else if ('\0' != mapped_nodes[0][2]) {
+                        j = strtoul(&mapped_nodes[0][2], NULL, 10);
+                    } else {
+                        /* add them all */
+                        j = orte_node_pool->size;
+                    }
+                    for (k=0; 0 < j && k < orte_node_pool->size; k++) {
+                        if (NULL != (node = (orte_node_t*)opal_pointer_array_get_item(orte_node_pool, k))) {
+                            if (0 == node->num_procs) {
+                                opal_argv_append_nosize(&mini_map, node->name);
+                                --j;
+                            }
+                        }
+                    }
+                } else if ('n' == mapped_nodes[i][1] ||
+                           'N' == mapped_nodes[i][1]) {
+                    /* they want a specific relative node #, so
+                     * look it up on global pool
+                     */
+                    nodeidx = strtol(&mapped_nodes[i][2], NULL, 10);
+                    if (nodeidx < 0 ||
+                        nodeidx > (int)orte_node_pool->size) {
+                        /* this is an error */
+                        orte_show_help("help-dash-host.txt", "dash-host:relative-node-out-of-bounds",
+                                       true, nodeidx, mapped_nodes[i]);
+                        rc = ORTE_ERR_SILENT;
+                        goto cleanup;
+                    }
+                    /* if the HNP is not allocated, then we need to
+                     * adjust the index as the node pool is offset
+                     * by one
+                     */
+                    if (!orte_hnp_is_allocated) {
+                        nodeidx++;
+                    }
+                    /* see if that location is filled */
+
+                    if (NULL == (node = (orte_node_t *) opal_pointer_array_get_item(orte_node_pool, nodeidx))) {
+                        /* this is an error */
+                        orte_show_help("help-dash-host.txt", "dash-host:relative-node-not-found",
+                                       true, nodeidx, mapped_nodes[i]);
+                        rc = ORTE_ERR_SILENT;
+                        goto cleanup;
+                    }
+                    /* add this node to the list */
+                    opal_argv_append_nosize(&mini_map, node->name);
+                } else {
+                    /* invalid relative node syntax */
+                    orte_show_help("help-dash-host.txt", "dash-host:invalid-relative-node-syntax",
+                                   true, mapped_nodes[i]);
+                    rc = ORTE_ERR_SILENT;
+                    goto cleanup;
+                }
+            }
+        } else {
+            /* just one node was given */
+            opal_argv_append_nosize(&mini_map, mapped_nodes[i]);
+        }
+    }
+    if (NULL == mini_map) {
+        rc = ORTE_SUCCESS;
+        goto cleanup;
+    }
+
     /*  go through the names found and
         add them to the host list. If they're not unique, then
         bump the slots count for each duplicate */
+    for (i=0; NULL != mini_map[i]; i++) {
+        OPAL_OUTPUT_VERBOSE((1, orte_ras_base_framework.framework_output,
+                             "%s dashhost: working node %s",
+                             ORTE_NAME_PRINT(ORTE_PROC_MY_NAME), mini_map[i]));
 
-    for (i = 0; NULL != mapped_nodes[i]; ++i) {
-        /* if the specified node contains a relative node syntax,
-         * this is an error
-         */
-        if ('+' == mapped_nodes[i][0]) {
-            orte_show_help("help-dash-host.txt", "dash-host:relative-syntax",
-                           true, mapped_nodes[i]);
-            rc = ORTE_ERR_SILENT;
-            goto cleanup;
-        }
         /* see if the node contains the number of slots */
         slots_given = false;
-        if (NULL != (cptr = strchr(mapped_nodes[i], ':'))) {
+        if (NULL != (cptr = strchr(mini_map[i], ':'))) {
             *cptr = '\0';
             ++cptr;
             if ('*' == *cptr) {
@@ -119,15 +193,11 @@ int orte_util_add_dash_host_nodes(opal_list_t *nodes,
             slots_given = true;
         }
 
-        OPAL_OUTPUT_VERBOSE((1, orte_ras_base_framework.framework_output,
-                             "%s dashhost: working node %s",
-                             ORTE_NAME_PRINT(ORTE_PROC_MY_NAME), mapped_nodes[i]));
-
         /* check for local name */
-        if (orte_ifislocal(mapped_nodes[i])) {
+        if (orte_ifislocal(mini_map[i])) {
             ndname = orte_process_info.nodename;
         } else {
-            ndname = mapped_nodes[i];
+            ndname = mini_map[i];
         }
 
         /* see if the node is already on the list */
@@ -177,6 +247,7 @@ int orte_util_add_dash_host_nodes(opal_list_t *nodes,
             opal_list_append(&adds, &node->super);
         }
     }
+    opal_argv_free(mini_map);
 
     /* transfer across all unique nodes */
     while (NULL != (item = opal_list_remove_first(&adds))) {
diff --git a/orte/util/dash_host/dash_host.h b/orte/util/dash_host/dash_host.h
index a11e36757e..abbdf505f9 100644
--- a/orte/util/dash_host/dash_host.h
+++ b/orte/util/dash_host/dash_host.h
@@ -9,7 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2014      Intel, Inc. All rights reserved.
+ * Copyright (c) 2014-2015 Intel, Inc. All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -31,7 +31,8 @@
 BEGIN_C_DECLS
 
 ORTE_DECLSPEC int orte_util_add_dash_host_nodes(opal_list_t *nodes,
-                                                char *hosts);
+                                                char *hosts,
+                                                bool allocating);
 
 ORTE_DECLSPEC int orte_util_filter_dash_host_nodes(opal_list_t *nodes,
                                                    char *hosts,