diff --git a/sys/net/sixlowpan/sixlowip.c b/sys/net/sixlowpan/sixlowip.c
index c5f86db952..b00d2b8775 100644
--- a/sys/net/sixlowpan/sixlowip.c
+++ b/sys/net/sixlowpan/sixlowip.c
@@ -112,7 +112,7 @@ void ipv6_process(void){
             }
             case(PROTO_NUM_NONE):{
                 //printf("Packet with no Header following the IPv6 Header received\n");
-                uint8_t *ptr = get_payload_buf(ipv6_ext_hdr_len);
+                //uint8_t *ptr = get_payload_buf(ipv6_ext_hdr_len);
                 printf("hello\n");
             }
             default:
@@ -243,7 +243,7 @@ void ipv6_get_saddr(ipv6_addr_t *src, ipv6_addr_t *dst){
 }
 
 uint8_t ipv6_get_addr_match(ipv6_addr_t *src, ipv6_addr_t *dst){
-    uint8_t val, xor;
+    uint8_t val = 0, xor;
     for(int i = 0; i < 16; i++){
         /* if bytes are equal add 8 */
         if(src->uint8[i] == dst->uint8[i]){
diff --git a/sys/net/sixlowpan/sixlowmac.c b/sys/net/sixlowpan/sixlowmac.c
index 6f96c9bd68..e40d300f7f 100644
--- a/sys/net/sixlowpan/sixlowmac.c
+++ b/sys/net/sixlowpan/sixlowmac.c
@@ -7,6 +7,7 @@
 #include "sixlownd.h"
 #include "sixlowpan.h"
 #include <ltc4150.h>
+#include <hwtimer.h>
 #include "thread.h"
 #include "msg.h"
 #include "radio/radio.h"
@@ -192,6 +193,7 @@ void send_ieee802154_frame(ieee_802154_long_t *addr, uint8_t *payload,
 void sixlowmac_init(transceiver_type_t type){
     int recv_pid = thread_create(radio_stack_buffer, RADIO_STACK_SIZE, 
                         PRIORITY_MAIN-2, CREATE_STACKTEST, recv_ieee802154_frame , "radio");
+    hwtimer_init();
     transceiver_type = type;
     transceiver_init(transceiver_type);
     transceiver_start();
diff --git a/sys/net/sixlowpan/sixlownd.c b/sys/net/sixlowpan/sixlownd.c
index d102467487..ca1043e43c 100644
--- a/sys/net/sixlowpan/sixlownd.c
+++ b/sys/net/sixlowpan/sixlownd.c
@@ -390,7 +390,7 @@ void recv_rtr_adv(void){
  
     int8_t trigger_ns = -1;
     int8_t abro_found = 0;
-    int16_t abro_version;
+    int16_t abro_version = 0;    // later replaced, just to supress warnings
     ipv6_addr_t abro_addr;
     
     lowpan_context_t *found_contexts[LOWPAN_CONTEXT_MAX];
@@ -624,7 +624,7 @@ void recv_nbr_sol(void){
         
     uint8_t send_na = 0;
     uint8_t sllao_set = 0;
-    uint8_t aro_state;
+    uint8_t aro_state = OPT_ARO_STATE_SUCCESS;
     
     /* check whick options are set, we need that because an aro
      * option condition is that a sllao option is set. thus that we don't 
@@ -714,11 +714,10 @@ void recv_nbr_sol(void){
                         nbr_entry = nbr_cache_search(&(ipv6_buf->srcaddr));
                         if(nbr_entry == NULL){
                             /* create neighbor cache */
-                            nbr_cache_add(&ipv6_buf->srcaddr,
-                                          &(opt_aro_buf->eui64),0,
-                                          NBR_STATUS_STALE, NBR_CACHE_TYPE_TEN,
-                                          opt_aro_buf->reg_ltime, NULL);
-                            aro_state = 0;
+                            aro_state = nbr_cache_add(&ipv6_buf->srcaddr,
+                                                      &(opt_aro_buf->eui64),0,
+                                                      NBR_STATUS_STALE, NBR_CACHE_TYPE_TEN,
+                                                      opt_aro_buf->reg_ltime, NULL);
                         } else {
                             if(memcmp(&(nbr_entry->addr.uint16[4]), 
                                &(opt_aro_buf->eui64.uint16[0]),8) == 0){
@@ -733,10 +732,11 @@ void recv_nbr_sol(void){
                                     nbr_entry->isrouter = 0;
                                     memcpy(&(nbr_entry->addr.uint8[0]),
                                            &(ipv6_buf->srcaddr.uint8[0]),16);
-                                }   
+                                }
+                                aro_state = OPT_ARO_STATE_SUCCESS;
                             } else {
                                 // duplicate found
-                                aro_state = 1;
+                                aro_state = OPT_ARO_STATE_DUP_ADDR;
                             }
                         } 
                     }
@@ -989,25 +989,28 @@ nbr_cache_t * nbr_cache_search(ipv6_addr_t *ipaddr){
     return NULL;
 }
 
-void nbr_cache_add(ipv6_addr_t *ipaddr, ieee_802154_long_t *laddr, 
+uint8_t nbr_cache_add(ipv6_addr_t *ipaddr, ieee_802154_long_t *laddr, 
                    uint8_t isrouter, uint8_t state, uint8_t type,
                    uint16_t ltime, ieee_802154_short_t *saddr){
     if(nbr_count == NBR_CACHE_SIZE){
         printf("ERROR: neighbor cache full\n");
-    } else {
-        memcpy(&(nbr_cache[nbr_count].addr), ipaddr, 16);
-        memcpy(&(nbr_cache[nbr_count].laddr), laddr, 8);
-        nbr_cache[nbr_count].isrouter = isrouter;
-        nbr_cache[nbr_count].state = state;
-        nbr_cache[nbr_count].type = type;
-        
-        timex_t t;
-        t.seconds = ltime;        
-        //vtimer_set_wakeup(&(nbr_cache[nbr_count].ltime), t, 
-        //                  nd_nbr_cache_rem_pid);        
-
-        nbr_count++;
+        return OPT_ARO_STATE_NBR_CACHE_FULL;
     }
+    
+    memcpy(&(nbr_cache[nbr_count].addr), ipaddr, 16);
+    memcpy(&(nbr_cache[nbr_count].laddr), laddr, 8);
+    nbr_cache[nbr_count].isrouter = isrouter;
+    nbr_cache[nbr_count].state = state;
+    nbr_cache[nbr_count].type = type;
+    
+    timex_t t;
+    t.seconds = ltime;        
+    //vtimer_set_wakeup(&(nbr_cache[nbr_count].ltime), t, 
+    //                  nd_nbr_cache_rem_pid);        
+
+    nbr_count++;
+    
+    return OPT_ARO_STATE_SUCCESS;
 }
 
 void nbr_cache_auto_rem(void){
diff --git a/sys/net/sixlowpan/sixlownd.h b/sys/net/sixlowpan/sixlownd.h
index 27d1ef6da2..ead7ae4c6b 100644
--- a/sys/net/sixlowpan/sixlownd.h
+++ b/sys/net/sixlowpan/sixlownd.h
@@ -51,6 +51,9 @@
 #define OPT_ARO_LEN                     2
 #define OPT_ARO_HDR_LEN                 16
 #define OPT_ARO_LTIME                   300 // geeigneten wert finden
+#define OPT_ARO_STATE_SUCCESS           0
+#define OPT_ARO_STATE_DUP_ADDR          1
+#define OPT_ARO_STATE_NBR_CACHE_FULL    2
 /* 6lowpan context option */
 #define OPT_6CO_TYPE                    32
 #define OPT_6CO_MIN_LEN                 2
@@ -221,7 +224,7 @@ abr_cache_t *abr_update_cache(
                     lowpan_context_t **contexts, uint8_t contexts_num,
                     plist_t **prefixes, uint8_t prefixes_num);
 nbr_cache_t * nbr_cache_search(ipv6_addr_t *ipaddr);
-void nbr_cache_add(ipv6_addr_t *ipaddr, ieee_802154_long_t *laddr,
+uint8_t nbr_cache_add(ipv6_addr_t *ipaddr, ieee_802154_long_t *laddr,
                    uint8_t isrouter, uint8_t state, uint8_t type,
                    uint16_t ltime, ieee_802154_short_t *saddr);
 void nbr_cache_auto_rem(void);