I appreciate this has been posted before but I think we have a slightly different situation.

Vigor 2927 - Firmware: 4.4.2.3

WAN 1 is connected to a BT Modem router over ethernet
WAN 2 is connected to Fibre Modem router with two Fixed IP's using Alias for the second IP.

Connectivity is all working as expected and we are using bothe WAN 2 IP without issue.

However, we keep getting these Fraggle Attack DoS notofications:

[DOS][Block][fraggle_attack][xxx.xxx.xxx.xxx:5678->255.255.255.255:5678][UDP][HLen=20, TLen=211]

The xxx.xxx.xxx.xxx IP is the gateway address for WAN 2.

The soluton refered to in this post: https://forum.draytek.co.uk/viewtopic.php?p=92864&hilit=fraggle#p92864 Is not appropriate as we do not have a DSL connection. Nor is there an option to disable [System Maintenance] > [Management] > DSL Status - Broadcast to LAN.

This issue started after our ISP added a second IP fixed IP to WAN 2 and installed a Mikrotik fibre modem.

As we have e-mail notifications we are getting bombarded with these Fraggle_attack notices. I could disable the DoS notification, but then that kind defeats the purpose of monitoring for DoS.

Any pointers would be great.

Thanks in advance

**Update**
It has been confirmed the Mikrotik was polling the neighbourhood. Similar to the Broadcast to LAN on the Draytek. This has been disabled on the Mikrotik and the Fraggle_attack messgaes have stopped!!.