incorrect ping

Hello.

Yesterday I found a really strange thing with ping on Mikrotiks.
Our customers complained, that connection drop.
I went ping from our main RB to furthermost RB for few hours without any packet drop or latency issue.
In the same time I went also PingPlotter, which showed me the issue - connection drop for about 1min each cca 30min.
Then I found, that second RB in our network was rebooted by watchdog (I made upgrade of antennas before) and booted somehow wrong, so Ethernet port for receive antenna dropped (I found it in log).

But how is possible, that all the time ping from mikrotiks show everything OK, otherwise that there was evidently problem?
I already head problem with ping, which showed me lower latency then it was. I found it by using traceroute, which worked OK in mikrotik…

What do you think?
Thanks

Is it possible that you have duplicate IPs? Can you check the ARP entries on both sides to see what the MAC address is?

Under IP/ARP I don’t have any duplicated IP. Also reboot of RB would not resolve the problem with dropping ethernet… (all IPs of RB are static)

Can you post a copy of the MikroTik config?

/export compact file=xyz

Here it is
Note: Two wirelles are disabled and not used anymore, addresses 10.0.9.0/24 are disabled, 10.0.14.0/24 I just moved to unused ethernet for compatibility (we have it probably somewhere e.g. as DNS server IP, so I don’t want to disable it…)
Mtik_exp.rsc (72.9 KB)