Download drastically dropped in simple home NAT

RouterOS Beginner Basics
1

Hello,
I’ve recently purchased a rb433 and configured it to masquerade to ether2 (WAN). I have a PC on ether1 (192.168.1.0/24). Everything is basically working, but my dl speed dropped from 20 mbit to ~1 mbit. When I connect my PC directly to the modem it’s back to normal.
My firewall settings are very simple:

 0   chain=input action=accept connection-state=established in-interface=ether2 
 1   chain=input action=accept connection-state=related in-interface=ether2 
 2   chain=input action=drop in-interface=ether2

RouterOS version 4.14.
Where the problem lies? How can I debug it?
I checked link quality with pingtest.com and got grade A, no packet loss.

Thanks

2

The input chain is for connections destined to the router.
The forward chain is for connections through the router

Please post your NAT configuration

3

I though it might be relevant to bandwidth anyway if messed up.



 0   chain=srcnat action=masquerade out-interface=ether2
4

Try upgrading to the latest version 5.6. Also you can send supout.rif file from this router to support@mikrotik.com and we will examine your configuration. There are many factors that could cause such problem.

5

I upgraded to 5.6 and it’s still slow. I also sent you the supout file.

6
  1. Have you set the same MAC address on ether2 as on your computer? Do you receive the same IP address via DHCP? Maybe it’s a problem with provider?
  2. What is the CPU load? Does profiler show anything interesting?
7

It’s not, I have added ether2 MAC to ISP’s list of authorized computers. I also called them about this and they said that everything looks ok.

CPU load is up to 3% during speedtest, profiler shows >95% idle.

8

The problem turned out to be.. bad cable. Shame on me. Now it works perfectly.