I have just started using my 2820vn but get between 3 and 5 "Mail alert from Router" emails a day all with the same type of message in them, e.g....

[DOS][Block][udp_flood, timeout=10][86.133.242.41:4500->86.133.242.41:62590][UDP][HLen=20, TLen=1376]
[DOS][Block][udp_flood, timeout=10][86.133.242.41:4500->86.133.242.41:62590][UDP][HLen=20, TLen=1376]
[DOS][Block][udp_flood, timeout=10][86.133.242.41:4500->86.133.242.41:62590][UDP][HLen=20, TLen=1376]
[DOS][Block][udp_flood, timeout=10][86.133.242.41:4500->86.133.242.41:62590][UDP][HLen=20, TLen=1376]
[DOS][Block][trace_route][86.133.242.41:12378->86.133.242.41:33436][UDP][HLen=20, TLen=32]
[DOS][Block][trace_route][86.133.242.41:12378->86.133.242.41:33436][UDP][HLen=20, TLen=32]
[DOS][Block][udp_flood, timeout=10][86.133.242.41:4500->86.133.242.41:62312][UDP][HLen=20, TLen=1376]
[DOS][Block][udp_flood, timeout=10][86.133.242.41:4500->86.133.242.41:62648][UDP][HLen=20, TLen=128]
[DOS][Block][udp_flood, timeout=10][86.133.242.41:4500->86.133.242.41:62648][UDP][HLen=20, TLen=912]

Where 86.133.242.41 is my WAN IP address. If I understand the log correctly it shows my Routers WAN interface is probing itself?

If anyone can help me understand this I would be gratefull. I searched the forum for "udp_flood" but it seems I am the only one where the IP is the same on both sides of the "->".

Thanks

RobinGB

Are you running a VPN through the router?

I ran into the same issue that was causing mayhem with my corporate VPN connection.

Then I found a post that talked about the router misinterpretting the VPN traffic as a udp_flood attack.

As soon as I turned off the DOS protection against udp_flood the VPN worked again and I stopped getting all the error messages.

Hope that helps.

Same thing here! I had an issue where the VPN kept dropping at random intervals - when I inspected the logs it was the same sort of message you were getting

i tuned off udp flood attack and no issues (yet!)