diff --git a/dist/tools/zep_dispatch/main.c b/dist/tools/zep_dispatch/main.c
index 6efac625e5..b889f36951 100644
--- a/dist/tools/zep_dispatch/main.c
+++ b/dist/tools/zep_dispatch/main.c
@@ -78,10 +78,10 @@ static void _send_topology(void *ctx, void *buffer, size_t len,
     uint8_t mac_src[8];
     uint8_t mac_src_len;
 
-    if (zep_parse_mac(buffer, len, mac_src, &mac_src_len) &&
-        topology_add(ctx, mac_src, mac_src_len, src_addr)) {
-        topology_send(ctx, sock, mac_src, mac_src_len, buffer, len);
+    if (zep_parse_mac(buffer, len, mac_src, &mac_src_len)) {
+        topology_add(ctx, mac_src, mac_src_len, src_addr);
     }
+    topology_send(ctx, sock, src_addr, buffer, len);
 }
 
 static void dispatch_loop(int sock, dispatch_cb_t dispatch, void *ctx)
diff --git a/dist/tools/zep_dispatch/topology.c b/dist/tools/zep_dispatch/topology.c
index 1744ba0229..1eabfb6907 100644
--- a/dist/tools/zep_dispatch/topology.c
+++ b/dist/tools/zep_dispatch/topology.c
@@ -198,7 +198,7 @@ int topology_parse(const char *file, topology_t *out)
 }
 
 void topology_send(const topology_t *t, int sock,
-                   const uint8_t *mac_src, size_t mac_src_len,
+                   const struct sockaddr_in6 *src_addr,
                    void *buffer, size_t len)
 {
     for (list_node_t *edge = t->edges.next; edge; edge = edge->next) {
@@ -208,8 +208,7 @@ void topology_send(const topology_t *t, int sock,
             continue;
         }
 
-        if ((mac_src_len == super->a->mac_len) &&
-            (memcmp(super->a->mac, mac_src, mac_src_len) == 0)) {
+        if (memcmp(&super->a->addr, src_addr, sizeof(*src_addr)) == 0) {
             /* packet loss */
             if (random() > super->weight_a_b * RAND_MAX) {
                 return;
@@ -219,8 +218,7 @@ void topology_send(const topology_t *t, int sock,
                    (struct sockaddr *)&super->b->addr,
                    sizeof(super->b->addr));
         }
-        else if ((mac_src_len == super->a->mac_len) &&
-                 (memcmp(super->b->mac, mac_src, mac_src_len) == 0)) {
+        else if (memcmp(&super->b->addr, src_addr, sizeof(*src_addr)) == 0) {
             /* packet loss */
             if (random() > super->weight_b_a * RAND_MAX) {
                 return;
diff --git a/dist/tools/zep_dispatch/topology.h b/dist/tools/zep_dispatch/topology.h
index 2232cc40aa..03499034b8 100644
--- a/dist/tools/zep_dispatch/topology.h
+++ b/dist/tools/zep_dispatch/topology.h
@@ -63,13 +63,12 @@ bool topology_add(topology_t *t, const uint8_t *mac, uint8_t mac_len,
  *
  * @param[in] t             topology to use
  * @param[in] sock          socket to use for sending
- * @param[in] mac_src       ZEP source l2 address
- * @param[in] mac_src_len   ZEP source l2 address length
+ * @param[in] src_addr      source node address
  * @param[in] buffer        ZEP frame to send
  * @param[in] len           ZEP frame length
  */
 void topology_send(const topology_t *t, int sock,
-                   const uint8_t *mac_src, size_t mac_src_len,
+                   const struct sockaddr_in6 *src_addr,
                    void *buffer, size_t len);
 
 #ifdef __cplusplus