Recently upgraded from BT Home Hub 5 to Smart Hub 2 for new BT Digital voice and after installing SH2 noticed large broadcast storms by using Wireshark on home PC network. There were 10 x STP broadcast frames every 3 seconds and filling Wireshark output. These were coming from the BT Smart Hub MAC address which uses an Arcadyn PHY MAC 44fe.3b76.aa88 sent as broadcast to 0180.c2ef.03fe
Just sharing how I stopped this LAN STP broadcast frames by using a MAC ACL on the ingress port to Cisco switch from BT router. After applying Wireshark stopped seeing L2 Arcadyn frames and all normal Layer 3 networking/web access was still working fine and network traffic level much calmer.
Stopped BT Arcadyn Broadcast STP Filtering on Cisco 2960L by MAC ACL
mac access-list extended drop_arcadyn
deny host 44fe.3b76.aa88 host 0180.c2ef.03fe
permit any any
Snippet of Cisco_Home 2960L port config to BT router, with additional MAc access-group :
interface GigabitEthernet0/24
description == BT Home Hub router ====
switchport access vlan 34
switchport mode access
mac access-group drop_arcadyn in
arp timeout 270
spanning-tree portfast edge
spanning-tree guard root
