What are those 2 errors ?

RouterOS General
1

See attached.

  1. shows weird logins, brute force. How to fix ?

  2. Why is the auto negotiation showing failed ??

2

screenshot 1 -
http://prntscr.com/8oti5d

screenshot 2 -
http://prntscr.com/8otitq

3

i only manage by winbox, disabling ssh telnet and web

if you need ssh and telnet you have to block it on input chain on connections incoming from wan interface

if you use mikrotik dns server be sure of block incoming from wan interface except dns servers you are using

the same if you use ntp server

4
  1. How to disable ?
  2. About DNS, how do I check, if Microtik DNS is used and how to disable ?
5

to disable in winbox go to ip – services

then disable unneeded, be carefully do not disable all

about dns in winbox go to ip – dns

if allow remote requests is unchecked no problem

if checked maybe your hosts are using the router to resolve dns queries, dont disable it, then block incoming from wan interface except dns servers ip you are using

6

screenshot 2 -
http://prntscr.com/8otitq

why is this showing failed ?