Hi All

Apologies if I have posted incorrectly, I am a noobie.

I am using a RB405G on OS 5.16 .. A dealer supplied and configured it.

We are experiencing a strange traffic phenomenon several times a day only on the external network side.
The router just starts sending and receiving traffic continuosly on the external side only. Coupled with this is cpu at +50% usage.
It gets so bad that normal internet use slows down to a dribble. I have unplugged the internal side of the network and it continues like this.
I have to disconnect the internet side and leave for a few minutes and reconnect, then everything returns to normal again.
This is resulting in incredibly high internet bandwidth usage been reported by my ISP.
There is a huge usage stat difference seen between the internal port and the external port. With the external port been +30% higher than internal side.
In last 30days internal = 200Gig / External =300Gig.

With internal side disconnected the RB firewall still shows many active connections sending and receiving at a high rate.

Anybody got any suggestions how to sort this out?

Thanks in advance.

I'd suggest you see if you have "/ip proxy" enabled - if you do, firewall it so only your interal IPs can get to it.

I'd suggest you see if you have "/ip proxy" enabled - if you do, firewall it so only your interal IPs can get to it.

Likewise, check you don't have an open DNS resolver (may be being used for an amplification attack).