diff --git a/os/net/app-layer/coap/coap.h b/os/net/app-layer/coap/coap.h
index 9d88886af..616f67d5c 100644
--- a/os/net/app-layer/coap/coap.h
+++ b/os/net/app-layer/coap/coap.h
@@ -46,7 +46,7 @@
 
 /* sanity check for configured values */
 #define COAP_MAX_PACKET_SIZE  (COAP_MAX_HEADER_SIZE + REST_MAX_CHUNK_SIZE)
-#if COAP_MAX_PACKET_SIZE > (UIP_BUFSIZE - UIP_IPH_LEN - UIP_UDPH_LEN)
+#if COAP_MAX_PACKET_SIZE > (UIP_BUFSIZE - UIP_LLH_LEN - UIP_IPH_LEN - UIP_UDPH_LEN)
 #error "UIP_CONF_BUFFER_SIZE too small for REST_MAX_CHUNK_SIZE"
 #endif
 
diff --git a/os/net/ipv6/multicast/esmrf.c b/os/net/ipv6/multicast/esmrf.c
index 2da8da400..adbea25e0 100644
--- a/os/net/ipv6/multicast/esmrf.c
+++ b/os/net/ipv6/multicast/esmrf.c
@@ -229,7 +229,7 @@ icmp_input()
 
   uip_process(UIP_UDP_SEND_CONN);
 
-  memcpy(&mcast_buf, uip_buf, uip_len);
+  memcpy(&mcast_buf, &uip_buf[UIP_LLH_LEN], uip_len);
   mcast_len = uip_len;
   /* pass the packet to our uip_process to check if it is allowed to
    * accept this packet or not */
@@ -239,7 +239,7 @@ icmp_input()
 
   uip_process(UIP_DATA);
 
-  memcpy(uip_buf, &mcast_buf, mcast_len);
+  memcpy(&uip_buf[UIP_LLH_LEN], &mcast_buf, mcast_len);
   uip_len = mcast_len;
   /* Return the IP of the original Multicast sender */
   uip_ipaddr_copy(&UIP_IP_BUF->srcipaddr, &src_ip);
@@ -257,7 +257,7 @@ icmp_input()
 static void
 mcast_fwd(void *p)
 {
-  memcpy(uip_buf, &mcast_buf, mcast_len);
+  memcpy(&uip_buf[UIP_LLH_LEN], &mcast_buf, mcast_len);
   uip_len = mcast_len;
   UIP_IP_BUF->ttl--;
   tcpip_output(NULL);
@@ -291,7 +291,7 @@ in()
   parent_lladdr = uip_ds6_nbr_lladdr_from_ipaddr(parent_ipaddr);
 
   if(parent_lladdr == NULL) {
-    PRINTF("ESMRF: NO Parent exist \n");
+    PRINTF("ESMRF: No Parent found\n");
     UIP_MCAST6_STATS_ADD(mcast_dropped);
     return UIP_MCAST6_DROP;
   }
@@ -309,6 +309,7 @@ in()
 
   if(UIP_IP_BUF->ttl <= 1) {
     UIP_MCAST6_STATS_ADD(mcast_dropped);
+    PRINTF("ESMRF: TTL too low\n");
     return UIP_MCAST6_DROP;
   }
 
@@ -350,12 +351,14 @@ in()
         fwd_delay = fwd_delay * (1 + ((random_rand() >> 11) % fwd_spread));
       }
 
-      memcpy(&mcast_buf, uip_buf, uip_len);
+      memcpy(&mcast_buf, &uip_buf[UIP_LLH_LEN], uip_len);
       mcast_len = uip_len;
       ctimer_set(&mcast_periodic, fwd_delay, mcast_fwd, NULL);
     }
     PRINTF("ESMRF: %u bytes: fwd in %u [%u]\n",
            uip_len, fwd_delay, fwd_spread);
+  } else {
+    PRINTF("ESMRF: Group unknown, dropping\n");
   }
 
   /* Done with this packet unless we are a member of the mcast group */
diff --git a/os/net/ipv6/multicast/roll-tm.c b/os/net/ipv6/multicast/roll-tm.c
index edf86b22b..1d19512d6 100644
--- a/os/net/ipv6/multicast/roll-tm.c
+++ b/os/net/ipv6/multicast/roll-tm.c
@@ -1321,7 +1321,7 @@ static void
 out()
 {
 
-  if(uip_len + HBHO_TOTAL_LEN > UIP_BUFSIZE) {
+  if(uip_len + HBHO_TOTAL_LEN > UIP_BUFSIZE - UIP_LLH_LEN) {
     PRINTF("ROLL TM: Multicast Out can not add HBHO. Packet too long\n");
     goto drop;
   }
diff --git a/os/net/ipv6/multicast/smrf.c b/os/net/ipv6/multicast/smrf.c
index 06167f75a..00043d60b 100644
--- a/os/net/ipv6/multicast/smrf.c
+++ b/os/net/ipv6/multicast/smrf.c
@@ -82,7 +82,7 @@ static uint8_t fwd_spread;
 static void
 mcast_fwd(void *p)
 {
-  memcpy(uip_buf, &mcast_buf, mcast_len);
+  memcpy(&uip_buf[UIP_LLH_LEN], &mcast_buf, mcast_len);
   uip_len = mcast_len;
   UIP_IP_BUF->ttl--;
   tcpip_output(NULL);
@@ -106,6 +106,7 @@ in()
    */
   d = rpl_get_any_dag();
   if(!d) {
+    PRINTF("SMRF: No DODAG\n");
     UIP_MCAST6_STATS_ADD(mcast_dropped);
     return UIP_MCAST6_DROP;
   }
@@ -115,6 +116,7 @@ in()
   parent_lladdr = uip_ds6_nbr_lladdr_from_ipaddr(parent_ipaddr);
 
   if(parent_lladdr == NULL) {
+    PRINTF("SMRF: No Parent found\n");
     UIP_MCAST6_STATS_ADD(mcast_dropped);
     return UIP_MCAST6_DROP;
   }
@@ -132,6 +134,7 @@ in()
 
   if(UIP_IP_BUF->ttl <= 1) {
     UIP_MCAST6_STATS_ADD(mcast_dropped);
+    PRINTF("SMRF: TTL too low\n");
     return UIP_MCAST6_DROP;
   }
 
@@ -173,12 +176,14 @@ in()
         fwd_delay = fwd_delay * (1 + ((random_rand() >> 11) % fwd_spread));
       }
 
-      memcpy(&mcast_buf, uip_buf, uip_len);
+      memcpy(&mcast_buf, &uip_buf[UIP_LLH_LEN], uip_len);
       mcast_len = uip_len;
       ctimer_set(&mcast_periodic, fwd_delay, mcast_fwd, NULL);
     }
     PRINTF("SMRF: %u bytes: fwd in %u [%u]\n",
            uip_len, fwd_delay, fwd_spread);
+  } else {
+    PRINTF("SMRF: Group unknown, dropping\n");
   }
 
   /* Done with this packet unless we are a member of the mcast group */
diff --git a/os/net/ipv6/sicslowpan.c b/os/net/ipv6/sicslowpan.c
index 4509c3e08..060699e93 100644
--- a/os/net/ipv6/sicslowpan.c
+++ b/os/net/ipv6/sicslowpan.c
@@ -123,7 +123,7 @@
 /* NOTE: In the multiple-reassembly context there is only room for the header / first fragment */
 #define SICSLOWPAN_IP_BUF(buf)   ((struct uip_ip_hdr *)buf)
 #define SICSLOWPAN_UDP_BUF(buf)  ((struct uip_udp_hdr *)&buf[UIP_IPH_LEN])
-#define SICSLOWPAN_IPPAYLOAD_BUF(buf) (&buf[UIP_LLIPH_LEN])
+#define SICSLOWPAN_IPPAYLOAD_BUF(buf) (&buf[UIP_IPH_LEN])
 
 
 #define UIP_IP_BUF          ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])
diff --git a/os/net/ipv6/tcpip.c b/os/net/ipv6/tcpip.c
index d6207400b..e096ce44b 100644
--- a/os/net/ipv6/tcpip.c
+++ b/os/net/ipv6/tcpip.c
@@ -472,12 +472,7 @@ output_fallback(void)
 #ifdef UIP_FALLBACK_INTERFACE
   LOG_INFO("fallback: removing ext hdrs & setting proto %d %d\n",
          uip_ext_len, *((uint8_t *)UIP_IP_BUF + 40));
-  if(uip_ext_len > 0) {
-    uint8_t proto = *((uint8_t *)UIP_IP_BUF + 40);
-    remove_ext_hdr();
-    /* This should be copied from the ext header... */
-    UIP_IP_BUF->proto = proto;
-  }
+  remove_ext_hdr();
   /* Inform the other end that the destination is not reachable. If it's
    * not informed routes might get lost unexpectedly until there's a need
    * to send a new packet to the peer */
diff --git a/os/net/ipv6/uip6.c b/os/net/ipv6/uip6.c
index 4ae366d2f..72384414a 100644
--- a/os/net/ipv6/uip6.c
+++ b/os/net/ipv6/uip6.c
@@ -523,6 +523,7 @@ uip_connect(const uip_ipaddr_t *ripaddr, uint16_t rport)
 void
 remove_ext_hdr(void)
 {
+  int last_uip_ext_len;
   /* Remove ext header before TCP/UDP processing. */
   if(uip_ext_len > 0) {
     LOG_DBG("Cutting ext-header before processing (extlen: %d, uiplen: %d)\n",
@@ -532,15 +533,17 @@ remove_ext_hdr(void)
       uip_clear_buf();
       return;
     }
-    memmove(((uint8_t *)UIP_TCP_BUF), (uint8_t *)UIP_TCP_BUF + uip_ext_len,
-            uip_len - UIP_IPH_LEN - uip_ext_len);
+    last_uip_ext_len = uip_ext_len;
+    uip_ext_len = 0;
+    UIP_IP_BUF->proto = UIP_EXT_BUF->next;
+    memmove(((uint8_t *)UIP_TCP_BUF), (uint8_t *)UIP_TCP_BUF + last_uip_ext_len,
+	    uip_len - UIP_IPH_LEN - last_uip_ext_len);
 
-    uip_len -= uip_ext_len;
+    uip_len -= last_uip_ext_len;
 
     /* Update the IP length. */
     UIP_IP_BUF->len[0] = (uip_len - UIP_IPH_LEN) >> 8;
     UIP_IP_BUF->len[1] = (uip_len - UIP_IPH_LEN) & 0xff;
-    uip_ext_len = 0;
   }
 }
 /*---------------------------------------------------------------------------*/
@@ -1494,7 +1497,6 @@ uip_process(uint8_t flag)
   udp_input:
 
   remove_ext_hdr();
-  UIP_IP_BUF->proto = UIP_PROTO_UDP;
 
   LOG_INFO("Receiving UDP packet\n");
 
@@ -1607,7 +1609,6 @@ uip_process(uint8_t flag)
   tcp_input:
 
   remove_ext_hdr();
-  UIP_IP_BUF->proto = UIP_PROTO_TCP;
 
   UIP_STAT(++uip_stat.tcp.recv);
   LOG_INFO("Receiving TCP packet\n");
diff --git a/os/net/ipv6/uipbuf.c b/os/net/ipv6/uipbuf.c
index c0f9da4e2..6ccbb99aa 100644
--- a/os/net/ipv6/uipbuf.c
+++ b/os/net/ipv6/uipbuf.c
@@ -128,6 +128,6 @@ uipbuf_clr_attr_flag(uint16_t flag)
 uint16_t
 uipbuf_is_attr_flag(uint16_t flag)
 {
-  return (uipbuf_attrs[UIPBUF_ATTR_FLAGS] & flag) > 0;
+  return (uipbuf_attrs[UIPBUF_ATTR_FLAGS] & flag) == flag;
 }
 /*---------------------------------------------------------------------------*/
diff --git a/os/net/ipv6/uipbuf.h b/os/net/ipv6/uipbuf.h
index 16b201843..337ffe17f 100644
--- a/os/net/ipv6/uipbuf.h
+++ b/os/net/ipv6/uipbuf.h
@@ -35,33 +35,106 @@
 
 #include "contiki.h"
 
-/* Get the next header given the buffer - start indicates that this is
-   start of the IPv6 header - needs to be set to 0 when in an ext hdr */
-
+/**
+ * \brief          Get the next IPv6 header.
+ * \param buffer   A pointer to the buffer holding the IPv6 packet
+ * \param size     The size of the data in the buffer
+ * \param protocol A pointer to a variable where the protocol of the header will be stored
+ * \param start    A flag that indicates if this is expected to be the IPv6 packet header or a later header (Extension header)
+ * \retval         returns address of the starting position of the next header
+ *
+ *                 This function moves to the next header in a IPv6 packet.
+ */
 uint8_t* uipbuf_get_next_header(uint8_t *buffer, uint16_t size, uint8_t *protocol, uint8_t start);
-/* Get the final header given the buffer - that is assumed to be at start
-   of an IPv6 header */
+
+
+/**
+ * \brief          Get the last IPv6 header.
+ * \param buffer   A pointer to the buffer holding the IPv6 packet
+ * \param size     The size of the data in the buffer
+ * \param protocol A pointer to a variable where the protocol of the header will be stored
+ * \retval         returns address of the starting position of the next header
+ *
+ *                 This function moves to the last header of the IPv6 packet.
+ */
 uint8_t* uipbuf_get_last_header(uint8_t *buffer, uint16_t size, uint8_t *protocol);
 
-/* Attributes relating to the current packet in uipbuf */
+
+/**
+ * \brief          Get the value of the attribute
+ * \param type     The attribute to get the value of
+ * \retval         the value of the attribute
+ *
+ *                 This function gets the value of a specific uipbuf attribute.
+ */
 uint16_t uipbuf_get_attr(uint8_t type);
-void uipbuf_set_attr_flag(uint16_t flag);
-void uipbuf_clr_attr_flag(uint16_t flag);
-uint16_t uipbuf_is_attr_flag(uint16_t flag);
+
+
+/**
+ * \brief          Set the value of the attribute
+ * \param type     The attribute to set the value of
+ * \param value    The value to set
+ * \retval         0 - indicates failure of setting the value
+ * \retval         1 - indicates success of setting the value
+ *
+ *                 This function sets the value of a specific uipbuf attribute.
+ */
 int uipbuf_set_attr(uint8_t type, uint16_t value);
+
+/**
+ * \brief          Set bits in the uipbuf attribute flags.
+ * \param flag_bits The bits to set in the flag.
+ *
+ *                 This function sets the uipbuf attributes flag of specified bits.
+ */
+void uipbuf_set_attr_flag(uint16_t flag_bits);
+
+/**
+ * \brief          Clear bits in the uipbuf attribute flags.
+ * \param flag_bits The bits to clear in the flag.
+ *
+ *                 This function clears the uipbuf attributes flag of specified bits.
+ */
+void uipbuf_clr_attr_flag(uint16_t flag_bits);
+
+/**
+ * \brief          Check if bits in the uipbuf attribute flag are set.
+ * \param flag_bits The bits to check in the flag.
+ *
+ *                 This function checks if the specified bits are set in the
+ *                 uipbuf attributes flag.
+ */
+uint16_t uipbuf_is_attr_flag(uint16_t flag_bits);
+
+
+/**
+ * \brief          Clear all attributes.
+ *
+ *                 This function clear all attributes in the uipbuf attributes
+ *                 including all flags.
+ */
 void uipbuf_clear_attr(void);
 
-/* These flags will be used for being */
+/**
+ * \brief The bits defined for uipbuf attributes flag.
+ *
+ */
+/* Avoid using NHC compression on the packet (6LoWPAN) */
 #define UIPBUF_ATTR_FLAGS_6LOWPAN_NO_NHC_COMPRESSION      0x01
+/* Avoid using prefix compression on the packet (6LoWPAN) */
 #define UIPBUF_ATTR_FLAGS_6LOWPAN_NO_PREFIX_COMPRESSION   0x02
 
+/**
+ * \brief The attributes defined for uipbuf attributes function.
+ *
+ */
 enum {
-  UIPBUF_ATTR_LLSEC_LEVEL,
-  UIPBUF_ATTR_LLSEC_KEY_ID,
-  UIPBUF_ATTR_INTERFACE_ID,
-  UIPBUF_ATTR_PHYSICAL_NETWORK_ID,
-  UIPBUF_ATTR_MAX_MAC_TRANSMISSIONS,
-  UIPBUF_ATTR_FLAGS,
+  UIPBUF_ATTR_LLSEC_LEVEL,      /**< Control link layer security level. */
+  UIPBUF_ATTR_LLSEC_KEY_ID,     /**< Control link layer security key ID. */
+  UIPBUF_ATTR_INTERFACE_ID,     /**< The interface to output packet on */
+  UIPBUF_ATTR_PHYSICAL_NETWORK_ID, /**< Physical network ID (mapped to PAN ID)*/
+  UIPBUF_ATTR_MAX_MAC_TRANSMISSIONS, /**< MAX transmissions of the packet MAC */
+  UIPBUF_ATTR_FLAGS,   /**< Flags that can control lower layers.  see above. */
   UIPBUF_ATTR_MAX
 };
 
diff --git a/os/net/rpl-classic/rpl-dag.c b/os/net/rpl-classic/rpl-dag.c
index e4f4191b1..aeed6194e 100644
--- a/os/net/rpl-classic/rpl-dag.c
+++ b/os/net/rpl-classic/rpl-dag.c
@@ -370,6 +370,7 @@ rpl_set_root(uint8_t instance_id, uip_ipaddr_t *dag_id)
         }
         if(dag == dag->instance->current_dag) {
           PRINTF("RPL: Dropping a joined DAG when setting this node as root");
+          rpl_set_default_route(instance, NULL);
           dag->instance->current_dag = NULL;
         } else {
           PRINTF("RPL: Dropping a DAG when setting this node as root");
@@ -522,14 +523,16 @@ rpl_set_prefix(rpl_dag_t *dag, uip_ipaddr_t *prefix, unsigned len)
   dag->prefix_info.length = len;
   dag->prefix_info.flags = UIP_ND6_RA_FLAG_AUTONOMOUS;
   PRINTF("RPL: Prefix set - will announce this in DIOs\n");
-  /* Autoconfigure an address if this node does not already have an address
-     with this prefix. Otherwise, update the prefix */
-  if(last_len == 0) {
-    PRINTF("rpl_set_prefix - prefix NULL\n");
-    check_prefix(NULL, &dag->prefix_info);
-  } else {
-    PRINTF("rpl_set_prefix - prefix NON-NULL\n");
-    check_prefix(&last_prefix, &dag->prefix_info);
+  if(dag->rank != ROOT_RANK(dag->instance)) {
+    /* Autoconfigure an address if this node does not already have an address
+       with this prefix. Otherwise, update the prefix */
+    if(last_len == 0) {
+      PRINTF("rpl_set_prefix - prefix NULL\n");
+      check_prefix(NULL, &dag->prefix_info);
+    } else {
+      PRINTF("rpl_set_prefix - prefix NON-NULL\n");
+      check_prefix(&last_prefix, &dag->prefix_info);
+    }
   }
   return 1;
 }
@@ -665,6 +668,10 @@ rpl_free_dag(rpl_dag_t *dag)
     if(RPL_IS_STORING(dag->instance)) {
       rpl_remove_routes(dag);
     }
+    /* Stop the DAO retransmit timer */
+#if RPL_WITH_DAO_ACK
+    ctimer_stop(&dag->instance->dao_retransmit_timer);
+#endif /* RPL_WITH_DAO_ACK */
 
    /* Remove autoconfigured address */
     if((dag->prefix_info.flags & UIP_ND6_RA_FLAG_AUTONOMOUS)) {
@@ -757,22 +764,17 @@ rpl_select_dag(rpl_instance_t *instance, rpl_parent_t *p)
   old_rank = instance->current_dag->rank;
   last_parent = instance->current_dag->preferred_parent;
 
-  best_dag = instance->current_dag;
-  if(best_dag->rank != ROOT_RANK(instance)) {
-    if(rpl_select_parent(p->dag) != NULL) {
-      if(p->dag != best_dag) {
-        best_dag = instance->of->best_dag(best_dag, p->dag);
-      }
-    } else if(p->dag == best_dag) {
-      best_dag = NULL;
-      for(dag = &instance->dag_table[0], end = dag + RPL_MAX_DAG_PER_INSTANCE; dag < end; ++dag) {
-        if(dag->used && dag->preferred_parent != NULL && dag->preferred_parent->rank != RPL_INFINITE_RANK) {
-          if(best_dag == NULL) {
-            best_dag = dag;
-          } else {
-            best_dag = instance->of->best_dag(best_dag, dag);
-          }
-        }
+  if(instance->current_dag->rank != ROOT_RANK(instance)) {
+    rpl_select_parent(p->dag);
+  }
+
+  best_dag = NULL;
+  for(dag = &instance->dag_table[0], end = dag + RPL_MAX_DAG_PER_INSTANCE; dag < end; ++dag) {
+    if(dag->used && dag->preferred_parent != NULL && dag->preferred_parent->rank != RPL_INFINITE_RANK) {
+      if(best_dag == NULL) {
+        best_dag = dag;
+      } else {
+        best_dag = instance->of->best_dag(best_dag, dag);
       }
     }
   }
@@ -1323,6 +1325,9 @@ rpl_local_repair(rpl_instance_t *instance)
 
   /* no downward route anymore */
   instance->has_downward_route = 0;
+#if RPL_WITH_DAO_ACK
+  ctimer_stop(&instance->dao_retransmit_timer);
+#endif /* RPL_WITH_DAO_ACK */
 
   rpl_reset_dio_timer(instance);
   if(RPL_IS_STORING(instance)) {
diff --git a/os/net/rpl-classic/rpl-ext-header.c b/os/net/rpl-classic/rpl-ext-header.c
index 0c1f8076a..083d26741 100644
--- a/os/net/rpl-classic/rpl-ext-header.c
+++ b/os/net/rpl-classic/rpl-ext-header.c
@@ -408,7 +408,7 @@ insert_srh_header(void)
       path_len, cmpri, cmpre, ext_len, padding);
 
   /* Check if there is enough space to store the extension header */
-  if(uip_len + ext_len > UIP_BUFSIZE) {
+  if(uip_len + ext_len > UIP_BUFSIZE - UIP_LLH_LEN) {
     PRINTF("RPL: Packet too long: impossible to add source routing header (%u bytes)\n", ext_len);
     return 0;
   }
@@ -553,7 +553,7 @@ insert_hbh_header(const rpl_instance_t *instance)
 
   /* Insert hop-by-hop header */
   PRINTF("RPL: Creating hop-by-hop option\n");
-  if(uip_len + RPL_HOP_BY_HOP_LEN > UIP_BUFSIZE) {
+  if(uip_len + RPL_HOP_BY_HOP_LEN > UIP_BUFSIZE - UIP_LLH_LEN) {
     PRINTF("RPL: Packet too long: impossible to add hop-by-hop option\n");
     uip_ext_len = last_uip_ext_len;
     return 0;
@@ -592,9 +592,11 @@ rpl_ext_header_remove(void)
 {
   uint8_t temp_len;
   uint8_t rpl_ext_hdr_len;
+  int uip_ext_opt_offset;
   uint8_t *uip_next_hdr;
 
   uip_ext_len = 0;
+  uip_ext_opt_offset = 2;
   uip_next_hdr = &UIP_IP_BUF->proto;
 
   /* Look for hop-by-hop and routing headers */
@@ -602,17 +604,22 @@ rpl_ext_header_remove(void)
     switch(*uip_next_hdr) {
       case UIP_PROTO_HBHO:
       case UIP_PROTO_ROUTING:
-        /* Remove hop-by-hop and routing headers */
-        *uip_next_hdr = UIP_EXT_BUF->next;
-        rpl_ext_hdr_len = (UIP_EXT_BUF->len * 8) + 8;
-        temp_len = UIP_IP_BUF->len[1];
-        uip_len -= rpl_ext_hdr_len;
-        UIP_IP_BUF->len[1] -= rpl_ext_hdr_len;
-        if(UIP_IP_BUF->len[1] > temp_len) {
-          UIP_IP_BUF->len[0]--;
+        if((*uip_next_hdr != UIP_PROTO_HBHO || UIP_EXT_HDR_OPT_RPL_BUF->opt_type == UIP_EXT_HDR_OPT_RPL)) {
+          /* Remove hop-by-hop and routing headers */
+          *uip_next_hdr = UIP_EXT_BUF->next;
+          rpl_ext_hdr_len = (UIP_EXT_BUF->len * 8) + 8;
+          temp_len = UIP_IP_BUF->len[1];
+          uip_len -= rpl_ext_hdr_len;
+          UIP_IP_BUF->len[1] -= rpl_ext_hdr_len;
+          if(UIP_IP_BUF->len[1] > temp_len) {
+            UIP_IP_BUF->len[0]--;
+          }
+          PRINTF("RPL: Removing RPL extension header (type %u, len %u)\n", *uip_next_hdr, rpl_ext_hdr_len);
+          memmove(UIP_EXT_BUF, ((uint8_t *)UIP_EXT_BUF) + rpl_ext_hdr_len, uip_len - UIP_IPH_LEN);
+        } else {
+          uip_next_hdr = &UIP_EXT_BUF->next;
+          uip_ext_len += (UIP_EXT_BUF->len << 3) + 8;
         }
-        PRINTF("RPL: Removing RPL extension header (type %u, len %u)\n", *uip_next_hdr, rpl_ext_hdr_len);
-        memmove(UIP_EXT_BUF, ((uint8_t *)UIP_EXT_BUF) + rpl_ext_hdr_len, uip_len - UIP_IPH_LEN);
         break;
       case UIP_PROTO_DESTO:
         /*
@@ -626,6 +633,7 @@ rpl_ext_header_remove(void)
         /* Move to next header */
         uip_next_hdr = &UIP_EXT_BUF->next;
         uip_ext_len += (UIP_EXT_BUF->len << 3) + 8;
+        break;
     default:
       return;
     }
diff --git a/os/net/rpl-classic/rpl-icmp6.c b/os/net/rpl-classic/rpl-icmp6.c
index 6da3c2656..c5114fd14 100644
--- a/os/net/rpl-classic/rpl-icmp6.c
+++ b/os/net/rpl-classic/rpl-icmp6.c
@@ -1282,6 +1282,12 @@ dao_ack_input(void)
     parent = NULL;
   }
 
+  if(instance->current_dag->rank == ROOT_RANK(instance)) {
+    PRINTF("RPL: DODAG root received a DAO ACK, ignoring it\n");
+    uip_clear_buf();
+    return;
+  }
+
   PRINTF("RPL: Received a DAO %s with sequence number %d (%d) and status %d from ",
          status < 128 ? "ACK" : "NACK",
          sequence, instance->my_dao_seqno, status);
diff --git a/os/net/rpl-classic/rpl-ns.h b/os/net/rpl-classic/rpl-ns.h
index f6ae4c2c6..dcc7e584a 100644
--- a/os/net/rpl-classic/rpl-ns.h
+++ b/os/net/rpl-classic/rpl-ns.h
@@ -56,6 +56,7 @@
 typedef struct rpl_ns_node {
   struct rpl_ns_node *next;
   uint32_t lifetime;
+  rpl_dag_t *dag;
   /* Store only IPv6 link identifiers as all nodes in the DAG share the same prefix */
   unsigned char link_identifier[8];
   struct rpl_ns_node *parent;
diff --git a/os/net/rpl-classic/rpl-private.h b/os/net/rpl-classic/rpl-private.h
index f00734821..723154cdd 100644
--- a/os/net/rpl-classic/rpl-private.h
+++ b/os/net/rpl-classic/rpl-private.h
@@ -199,13 +199,6 @@
 #define RPL_ROUTE_FROM_MULTICAST_DAO    2
 #define RPL_ROUTE_FROM_DIO              3
 
-/* Multicast Route Lifetime as a multiple of the lifetime unit */
-#ifdef RPL_CONF_MCAST_LIFETIME
-#define RPL_MCAST_LIFETIME RPL_CONF_MCAST_LIFETIME
-#else
-#define RPL_MCAST_LIFETIME 3
-#endif
-
 /* DIS related */
 #define RPL_DIS_SEND                    1
 
diff --git a/os/net/rpl-classic/rpl-timers.c b/os/net/rpl-classic/rpl-timers.c
index b89a1258d..7742a5fcc 100644
--- a/os/net/rpl-classic/rpl-timers.c
+++ b/os/net/rpl-classic/rpl-timers.c
@@ -283,7 +283,7 @@ handle_dao_timer(void *ptr)
         if(uip_ds6_if.maddr_list[i].isused
             && uip_is_addr_mcast_global(&uip_ds6_if.maddr_list[i].ipaddr)) {
           dao_output_target(instance->current_dag->preferred_parent,
-              &uip_ds6_if.maddr_list[i].ipaddr, RPL_MCAST_LIFETIME);
+              &uip_ds6_if.maddr_list[i].ipaddr, instance->default_lifetime);
         }
       }
 
@@ -293,7 +293,7 @@ handle_dao_timer(void *ptr)
         /* Don't send if it's also our own address, done that already */
         if(uip_ds6_maddr_lookup(&mcast_route->group) == NULL) {
           dao_output_target(instance->current_dag->preferred_parent,
-                     &mcast_route->group, RPL_MCAST_LIFETIME);
+                     &mcast_route->group, instance->default_lifetime);
         }
         mcast_route = list_item_next(mcast_route);
       }
@@ -457,11 +457,29 @@ get_probing_target(rpl_dag_t *dag)
   return probing_target;
 }
 /*---------------------------------------------------------------------------*/
+static rpl_dag_t *
+get_next_dag(rpl_instance_t *instance)
+{
+  rpl_dag_t *dag = NULL;
+  int new_dag = instance->last_dag;
+  do {
+    new_dag++;
+    if(new_dag >= RPL_MAX_DAG_PER_INSTANCE) {
+      new_dag = 0;
+    }
+    if(instance->dag_table[new_dag].used) {
+      dag = &instance->dag_table[new_dag];
+    }
+  } while(new_dag != instance->last_dag && dag == NULL);
+  instance->last_dag = new_dag;
+  return dag;
+}
+/*---------------------------------------------------------------------------*/
 static void
 handle_probing_timer(void *ptr)
 {
   rpl_instance_t *instance = (rpl_instance_t *)ptr;
-  rpl_parent_t *probing_target = RPL_PROBING_SELECT_FUNC(instance->current_dag);
+  rpl_parent_t *probing_target = RPL_PROBING_SELECT_FUNC(get_next_dag(instance));
   uip_ipaddr_t *target_ipaddr = rpl_parent_get_ipaddr(probing_target);
 
   /* Perform probing */
diff --git a/os/net/rpl-classic/rpl.h b/os/net/rpl-classic/rpl.h
index 185bcbef2..2fe9f1dbf 100644
--- a/os/net/rpl-classic/rpl.h
+++ b/os/net/rpl-classic/rpl.h
@@ -252,6 +252,7 @@ struct rpl_instance {
 #if RPL_WITH_PROBING
   struct ctimer probing_timer;
   rpl_parent_t *urgent_probing_target;
+  int last_dag;
 #endif /* RPL_WITH_PROBING */
   struct ctimer dio_timer;
   struct ctimer dao_timer;
diff --git a/os/net/rpl-lite/rpl-ext-header.c b/os/net/rpl-lite/rpl-ext-header.c
index e71e6c1f6..6031d7eef 100644
--- a/os/net/rpl-lite/rpl-ext-header.c
+++ b/os/net/rpl-lite/rpl-ext-header.c
@@ -302,7 +302,7 @@ insert_srh_header(void)
       path_len, cmpri, cmpre, ext_len, padding);
 
   /* Check if there is enough space to store the extension header */
-  if(uip_len + ext_len > UIP_BUFSIZE) {
+  if(uip_len + ext_len > UIP_BUFSIZE - UIP_LLH_LEN) {
     LOG_ERR("packet too long: impossible to add source routing header (%u bytes)\n", ext_len);
     return 0;
   }
@@ -464,7 +464,7 @@ insert_hbh_header(void)
 
   /* Insert hop-by-hop header */
   LOG_INFO("creating hop-by-hop option\n");
-  if(uip_len + RPL_HOP_BY_HOP_LEN > UIP_BUFSIZE) {
+  if(uip_len + RPL_HOP_BY_HOP_LEN > UIP_BUFSIZE - UIP_LLH_LEN) {
     LOG_ERR("packet too long: impossible to add hop-by-hop option\n");
     uip_ext_len = last_uip_ext_len;
     return 0;
@@ -531,9 +531,11 @@ rpl_ext_header_remove(void)
 {
   uint8_t temp_len;
   uint8_t rpl_ext_hdr_len;
+  int uip_ext_opt_offset;
   uint8_t *uip_next_hdr;
 
   uip_ext_len = 0;
+  uip_ext_opt_offset = 2;
   uip_next_hdr = &UIP_IP_BUF->proto;
 
   /* Look for hop-by-hop and routing headers */
@@ -541,17 +543,22 @@ rpl_ext_header_remove(void)
     switch(*uip_next_hdr) {
       case UIP_PROTO_HBHO:
       case UIP_PROTO_ROUTING:
-        /* Remove hop-by-hop and routing headers */
-        *uip_next_hdr = UIP_EXT_BUF->next;
-        rpl_ext_hdr_len = (UIP_EXT_BUF->len * 8) + 8;
-        temp_len = UIP_IP_BUF->len[1];
-        uip_len -= rpl_ext_hdr_len;
-        UIP_IP_BUF->len[1] -= rpl_ext_hdr_len;
-        if(UIP_IP_BUF->len[1] > temp_len) {
-          UIP_IP_BUF->len[0]--;
+        if((*uip_next_hdr != UIP_PROTO_HBHO || UIP_EXT_HDR_OPT_RPL_BUF->opt_type == UIP_EXT_HDR_OPT_RPL)) {
+          /* Remove hop-by-hop and routing headers */
+          *uip_next_hdr = UIP_EXT_BUF->next;
+          rpl_ext_hdr_len = (UIP_EXT_BUF->len * 8) + 8;
+          temp_len = UIP_IP_BUF->len[1];
+          uip_len -= rpl_ext_hdr_len;
+          UIP_IP_BUF->len[1] -= rpl_ext_hdr_len;
+          if(UIP_IP_BUF->len[1] > temp_len) {
+            UIP_IP_BUF->len[0]--;
+          }
+          LOG_INFO("removing RPL extension header (type %u, len %u)\n", *uip_next_hdr, rpl_ext_hdr_len);
+          memmove(UIP_EXT_BUF, ((uint8_t *)UIP_EXT_BUF) + rpl_ext_hdr_len, uip_len - UIP_IPH_LEN);
+        } else {
+          uip_next_hdr = &UIP_EXT_BUF->next;
+          uip_ext_len += (UIP_EXT_BUF->len << 3) + 8;
         }
-        LOG_INFO("removing RPL extension header (type %u, len %u)\n", *uip_next_hdr, rpl_ext_hdr_len);
-        memmove(UIP_EXT_BUF, ((uint8_t *)UIP_EXT_BUF) + rpl_ext_hdr_len, uip_len - UIP_IPH_LEN);
         break;
       case UIP_PROTO_DESTO:
         /*
@@ -565,6 +572,7 @@ rpl_ext_header_remove(void)
         /* Move to next header */
         uip_next_hdr = &UIP_EXT_BUF->next;
         uip_ext_len += (UIP_EXT_BUF->len << 3) + 8;
+        break;
     default:
       return;
     }
diff --git a/os/services/ip64/ip64-dhcpc.c b/os/services/ip64/ip64-dhcpc.c
index 81d97490d..8e8e286f8 100644
--- a/os/services/ip64/ip64-dhcpc.c
+++ b/os/services/ip64/ip64-dhcpc.c
@@ -61,7 +61,7 @@ struct dhcp_msg {
   uint8_t options[312];
 };
 
-#if (UIP_BUFSIZE - UIP_UDPIP_HLEN) < 548
+#if (UIP_BUFSIZE - UIP_LLH_LEN - UIP_UDPIP_HLEN) < 548
 #error UIP_CONF_BUFFER_SIZE may be too small to accomodate DHCPv4 packets
 #error Increase UIP_CONF_BUFFER_SIZE in your project-conf.h, or contiki-conf.h
 #error A good size is 600 bytes