1 files changed, 10 insertions, 2 deletions

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 948860a2a576..22bc65102370 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -146,8 +146,10 @@ static int batadv_interface_tx(struct sk_buff *skb,
         struct batadv_bcast_packet *bcast_packet;
         struct vlan_ethhdr *vhdr;
         __be16 ethertype = __constant_htons(BATADV_ETH_P_BATMAN);
-        static const uint8_t stp_addr[ETH_ALEN] = {0x01, 0x80, 0xC2, 0x00, 0x00,
-                                                   0x00};
+        static const uint8_t stp_addr[ETH_ALEN] = {0x01, 0x80, 0xC2, 0x00,
+                                                   0x00, 0x00};
+        static const uint8_t ectp_addr[ETH_ALEN] = {0xCF, 0x00, 0x00, 0x00,
+                                                    0x00, 0x00};
         unsigned int header_len = 0;
         int data_len = skb->len, ret;
         short vid __maybe_unused = -1;
@@ -180,10 +182,16 @@ static int batadv_interface_tx(struct sk_buff *skb,
 
         /* don't accept stp packets. STP does not help in meshes.
          * better use the bridge loop avoidance ...
+         *
+         * The same goes for ECTP sent at least by some Cisco Switches,
+         * it might confuse the mesh when used with bridge loop avoidance.
          */
         if (batadv_compare_eth(ethhdr->h_dest, stp_addr))
                 goto dropped;
 
+        if (batadv_compare_eth(ethhdr->h_dest, ectp_addr))
+                goto dropped;
+
         if (is_multicast_ether_addr(ethhdr->h_dest)) {
                 do_bcast = true;