diff --git a/sys/include/net/ipv6/addr.h b/sys/include/net/ipv6/addr.h
index b43562b08a..376d8598fd 100644
--- a/sys/include/net/ipv6/addr.h
+++ b/sys/include/net/ipv6/addr.h
@@ -729,6 +729,20 @@ char *ipv6_addr_to_str(char *result, const ipv6_addr_t *addr, uint8_t result_len
  */
 ipv6_addr_t *ipv6_addr_from_str(ipv6_addr_t *result, const char *addr);
 
+/**
+ * @brief split IPv6 address string representation and return remaining string
+ *
+ * Will change @p separator position in @p addr_str to '\0'
+ *
+ * @param[in,out]   addr_str    Address to split
+ * @param[in]       separator   Separator char to use
+ *
+ * @return      string following the first occurrence of @p separator in
+ *              @p addr_str.
+ * @return      NULL if @p separator was not found.
+ */
+char *ipv6_addr_split_str(char *addr_str, char separator);
+
 /**
  * @brief split IPv6 address string representation
  *
@@ -741,7 +755,7 @@ ipv6_addr_t *ipv6_addr_from_str(ipv6_addr_t *result, const char *addr);
  * @return      atoi(string after split)
  * @return      @p _default if no string after @p seperator
  */
-int ipv6_addr_split(char *addr_str, char seperator, int _default);
+int ipv6_addr_split_int(char *addr_str, char seperator, int _default);
 
 /**
  * @brief split IPv6 prefix string representation
@@ -753,7 +767,7 @@ int ipv6_addr_split(char *addr_str, char seperator, int _default);
  */
 static inline int ipv6_addr_split_prefix(char *addr_str)
 {
-    return ipv6_addr_split(addr_str, '/', 128);
+    return ipv6_addr_split_int(addr_str, '/', 128);
 }
 
 /**
@@ -762,11 +776,12 @@ static inline int ipv6_addr_split_prefix(char *addr_str)
  * E.g., "fe80::1%5" returns "5", changes @p addr_str to "fe80::1"
  *
  * @param[in,out]   addr_str Address to split
- * @return          interface number or -1 if none specified
+ * @return          string containing the interface specifier.
+ * @return          NULL if no interface was specified.
  */
-static inline int ipv6_addr_split_iface(char *addr_str)
+static inline char *ipv6_addr_split_iface(char *addr_str)
 {
-    return ipv6_addr_split(addr_str, '%', -1);
+    return ipv6_addr_split_str(addr_str, '%');
 }
 
 /**
diff --git a/sys/net/network_layer/ipv6/addr/ipv6_addr.c b/sys/net/network_layer/ipv6/addr/ipv6_addr.c
index 29d8a07817..60f88e7075 100644
--- a/sys/net/network_layer/ipv6/addr/ipv6_addr.c
+++ b/sys/net/network_layer/ipv6/addr/ipv6_addr.c
@@ -123,20 +123,23 @@ void ipv6_addr_init_iid(ipv6_addr_t *out, const uint8_t *iid, uint8_t bits)
     memcpy(&(out->u8[pos]), iid, bytes);
 }
 
-int ipv6_addr_split(char *addr_str, char seperator, int _default)
+char *ipv6_addr_split_str(char *addr_str, char seperator)
 {
     char *sep = addr_str;
-    while(*++sep) {
+    while (*(++sep)) {
         if (*sep == seperator) {
             *sep++ = '\0';
-            if (*sep) {
-                _default = atoi(sep);
-            }
             break;
         }
     }
 
-    return _default;
+    return *sep ? sep : NULL;
+}
+
+int ipv6_addr_split_int(char *addr_str, char separator, int _default)
+{
+    char *val = ipv6_addr_split_str(addr_str, separator);
+    return val ? atoi(val) : _default;
 }
 
 void ipv6_addr_print(const ipv6_addr_t *addr)