diff --git a/overlay_mdp_services.c b/overlay_mdp_services.c
index 478e2c0c..a186bb54 100644
--- a/overlay_mdp_services.c
+++ b/overlay_mdp_services.c
@@ -26,6 +26,19 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include "mdp_client.h"
 #include "crypto.h"
 
+int overlay_mdp_service_rhizomerequest(overlay_mdp_frame *mdp)
+{
+  IN();
+
+  RETURN(-1);
+}
+
+int overlay_mdp_service_rhizomeresponse(overlay_mdp_frame *mdp)
+{
+  IN();
+
+  RETURN(-1);
+}
 
 int overlay_mdp_service_dnalookup(overlay_mdp_frame *mdp)
 {
@@ -133,19 +146,12 @@ int overlay_mdp_try_interal_services(overlay_mdp_frame *mdp)
 {
   IN();
   switch(mdp->out.dst.port) {
-  case MDP_PORT_VOMP:
-    RETURN(vomp_mdp_received(mdp));
-  case MDP_PORT_KEYMAPREQUEST:
-    /* Either respond with the appropriate SAS, or record this one if it
-       verifies out okay. */
-    if (debug & DEBUG_MDPREQUESTS) DEBUG("MDP_PORT_KEYMAPREQUEST");
-    RETURN(keyring_mapping_request(keyring,mdp));
-  case MDP_PORT_DNALOOKUP: /* attempt to resolve DID to SID */
-    RETURN(overlay_mdp_service_dnalookup(mdp));
-    break;
-  case MDP_PORT_ECHO: /* well known ECHO port for TCP/UDP and now MDP */
-    RETURN(overlay_mdp_service_echo(mdp));
-    break;
+  case MDP_PORT_VOMP:             RETURN(vomp_mdp_received(mdp));
+  case MDP_PORT_KEYMAPREQUEST:    RETURN(keyring_mapping_request(keyring,mdp));
+  case MDP_PORT_DNALOOKUP:        RETURN(overlay_mdp_service_dnalookup(mdp));
+  case MDP_PORT_ECHO:             RETURN(overlay_mdp_service_echo(mdp));
+  case MDP_PORT_RHIZOME_REQUEST:  RETURN(overlay_mdp_service_rhizomerequest(mdp));
+  case MDP_PORT_RHIZOME_RESPONSE: RETURN(overlay_mdp_service_rhizomeresponse(mdp));
   default:
     /* Unbound socket.  We won't be sending ICMP style connection refused
        messages, partly because they are a waste of bandwidth. */
diff --git a/packetformats.c b/packetformats.c
index be8bbb9e..ea1bd24d 100644
--- a/packetformats.c
+++ b/packetformats.c
@@ -40,3 +40,24 @@ int packetOk(struct overlay_interface *interface, unsigned char *packet, size_t
   return WHY("Packet type not recognised.");
 }
 
+void write_uint64(unsigned char *o,uint64_t v)
+{
+  int i;
+  for(i=0;i<8;i++)
+    { *(o++)=v&0xff; v=v>>8; }
+}
+
+void write_uint32(unsigned char *o,uint32_t v)
+{
+  int i;
+  for(i=0;i<4;i++)
+    { *(o++)=v&0xff; v=v>>8; }
+}
+
+void write_uint16(unsigned char *o,uint16_t v)
+{
+  int i;
+  for(i=0;i<2;i++)
+    { *(o++)=v&0xff; v=v>>8; }
+}
+
diff --git a/rhizome_fetch.c b/rhizome_fetch.c
index b515f919..aca2caf4 100644
--- a/rhizome_fetch.c
+++ b/rhizome_fetch.c
@@ -1036,10 +1036,17 @@ static int rhizome_fetch_mdp_requestblocks(struct rhizome_fetch_slot *slot)
   mdp.out.dst.port=MDP_PORT_RHIZOME_REQUEST;
   mdp.out.ttl=1;
   mdp.packetTypeAndFlags=MDP_TX;
-  DEBUGF("Set request manifest in MDP frame body");
+
+  mdp.out.queue=OQ_ORDINARY;
+  mdp.out.payload_length=RHIZOME_BAR_BYTES+8+4+2;
+  bcopy(slot->bar,&mdp.out.payload[0],RHIZOME_BAR_BYTES);
+
+  write_uint64(&mdp.out.payload[RHIZOME_BAR_BYTES],slot->mdpRXWindowStart);
+  write_uint32(&mdp.out.payload[RHIZOME_BAR_BYTES+8],slot->mdpRXBitmap);
+  write_uint16(&mdp.out.payload[RHIZOME_BAR_BYTES+8+4],slot->mdpRXBlockLength);
+
   overlay_mdp_dispatch(&mdp,0 /* system generated */,NULL,0);
   
-  DEBUGF("Set callback function, and set alarm");
   slot->alarm.function = rhizome_fetch_mdp_slot_callback;
   slot->alarm.alarm=slot->mdpNextTX;
   schedule(&slot->alarm);
@@ -1049,6 +1056,11 @@ static int rhizome_fetch_mdp_requestblocks(struct rhizome_fetch_slot *slot)
 
 static int rhizome_fetch_mdp_requestmanifest(struct rhizome_fetch_slot *slot)
 {
+  if (slot->prefix_length<1||slot->prefix_length>32) {
+    // invalid request
+    return rhizome_fetch_close(slot);
+  }
+
   if ((gettime_ms()-slot->mdpLastRX)>slot->mdpIdleTimeout) {
     // connection timed out
     return rhizome_fetch_close(slot);
@@ -1065,7 +1077,11 @@ static int rhizome_fetch_mdp_requestmanifest(struct rhizome_fetch_slot *slot)
   mdp.out.dst.port=MDP_PORT_RHIZOME_REQUEST;
   mdp.out.ttl=1;
   mdp.packetTypeAndFlags=MDP_TX;
-  DEBUGF("Set request manifest in MDP frame body");
+
+  mdp.out.queue=OQ_ORDINARY;
+  mdp.out.payload_length=slot->prefix_length;
+  bcopy(slot->prefix,&mdp.out.payload[0],slot->prefix_length);
+
   overlay_mdp_dispatch(&mdp,0 /* system generated */,NULL,0);
   
   DEBUGF("Set callback function, and set alarm");
diff --git a/serval.h b/serval.h
index 8649f8e2..5be1ce15 100644
--- a/serval.h
+++ b/serval.h
@@ -765,4 +765,8 @@ void dump_stack();
 int olsr_init_socket(void);
 int olsr_send(struct overlay_frame *frame);
 
+void write_uint64(unsigned char *o,uint64_t v);
+void write_uint16(unsigned char *o,uint16_t v);
+void write_uint32(unsigned char *o,uint32_t v);
+
 #endif // __SERVALD_SERVALD_H