There is a big and very serious problem.
I have HDSL asymmetric 40/4 Mbit / s, it seems to me it working well.
DGT is the first router (routrer edge), it gives the first NAT (dynamic external ip to internal ip: 100.100.100.49/29), there is a MikroTik RB750 behind it. MiTk is doing the "right" NAT (100.100.100.49/29 into 192.168.88.0/24) and dividing bandwidth (QoS sq and qt with the L7 and DHCP).
And now the most important: irregularly, several times during the week or several times per day or per few hours LAN interface is clogging the movement of 12 - 13 thousand p/s (sic!). In general, connection with the world does not work at all. Then I can connect to the MikroTik only using MAC addres (ip addres don't work). In the logs there is nothing wrong. Link monitoring indicates thousands of udp packets on (unknown me) unspecified IP ("select" IP is unknown to me, sometimes it is external ip address from outside the class LAN, other times it is the LAN IP). In this "hiccup" usually helps current reboot all devices on the LAN (all threeswitches and Mikrotik router). There are situations that everything just goes back to normal by itself. At first I thought I made a few mistakes in configuration of Mikrotick. I consulted my settings and they are correct. Then I thought it might be broken port (switch) or Mikrotik. I replaced the broken equipment for the new one from factory, and .... NOTHING. Situation repeats itself.
It's seems to be like DDoS but I'm not sure. Maybe Mikrotik (ver. 5.23) has some bugs?
Someone HELP ME please!
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Can you please try same configuration under ROS 4.17? I've lost connections and reboots under 5.x undear heavy load. RB750G with same configuration doesn't reboots itself.