Hi at all,

I'm very disappointed in Mikrotik support!
I opened a urgend ticket (Ticket#2018021122000651 on 11th of February) because I've troubles at many of my customers using Mikrotik wifi equipment.
There was only a short answer without any real help...
Don't know what to do...

Also postet the problem here:

viewtopic.php?f=7&t=120218&p=641323#p6

post #45

Please help!

Cheers

Marcel

What was the response from Mikrotik Support?

Have you tried engaging the developers of the App?

Hi CZfan,

The Mikrotik Support response from 2th of May was:
"Hello, we could try to check this setup but we can't guaranty that we will allocate lot of resources for this problem."

Sadly that was the last answer.
After that I send them some more mails but until today there was no further answer.

I also contacted the App developer; for this problem and some other research they send the Chief- App- Developer to one of my biggest customers to analyze.
He found out that the client devices that connect to a local central database sporadically lose their TCP connection.
Client=iPod /iPhone via wifi 5GHz
Central Database=iPad via ethernetadapter

And this happens only with mikrotik wifi devices.
No Problems with Cisco, Lancom, Bintec, TP-link, Apple Extreme, Aerohive, Ubiquiti!

So this is clearly an Mikrotik problem

I gave them all credentials for the app activation and a detailled howto...

I am no expert in this, your best hope is @sindy sees this and jumps in.

Based on the captures posted in your previous post here, viewtopic.php?f=7&t=120218&p=641323#p641323

I will start looking at the database sever, my reasoning is as per screenshot below from those captures, the client sends an ACK to server, no response from the server, so then 17 seconds later, sends another ACK, again no response and another 17 seconds later another ACK, which is then immediately followed by a reset from the database server with a window size of 0, meaning buffer is full and can't receive more.

Sindy sees it but has no idea what it might be.

If I get it right:

• while the TCP connection between a wireless device and the .10 is down, the wireless device continues to see internet, so the wireless connection itself is not down, and even the .10 and the other device can ping each other during that time
• in one arrangement, the .10 device is connected using a cable durectly to ether3, the other devices are connected wirelessly
• in another arrangement, .10 is connected wirelessly too, and the behaviour is the same - TCP down but other communication (ping) is OK
• if an AP of some other vendor is used, the issue doesn't happen
• the capture at ether3 was done using Mikrotik's sniffer

Correct in all points?

If so, can you sniff using Wireshark directly at the .10 device while it is connected to Mikrotik's ether3 and simultaneously sniff on Mikrotik into a file?

The only scenario I can imagine where Mikrotik would be the source of the trouble is that the frames are sent on ether3 with a wrong FCS so the receiving device drops them, or not sent at all despite being shown in the sniff. In either of these cases, you would see them in the sniff from the Mikrotik but not in the sniff from the .10.

Try to dissable wlan security. This is sometimes magic to apple devices.

The capture shows that the frames have been received from the air and forwarded to ether3. So if wireless security should be involved, they would have to be improperly decrypted and thus made incomprehensible to the recipient. Is this what you have in mind? However, the TCP checksum of the retransmitted packets is correct, which should not be the case if the frames would be corrupt during decryption.

well. I have newer figured out why apple devices acct like this. I have read a lot of capture etc - and can just tell that dissabeling security will do magic to apple devices. If ita a apple or mikrotik bug - i dont know. Im quite a miktorik evangalist - but to wlan where i dont have 100% control of devices - like iphone - i sometimes just hate mikrotik.

@OP, you are now in very good hands with sindy and I can guarantee you, by providing all info requested, you will get to the bottom of your problem.

@sindy, thank you for taking note and assist and I am looking forward to learning from you during this process.

@samsung172, I had issues with Apple devices even with expensive Ruckus devices, so I do not believe the Common point is Mikrotik, but rather Apple, but it will be very interesting to see what comes out here

@OP, you are now in very good hands with sindy and I can guarantee you, by providing all info requested, you will get to the bottom of your problem.

@sindy, thank you for taking note and assist and I am looking forward to learning from you during this process.

@samsung172, I had issues with Apple devices even with expensive Ruckus devices, so I do not believe the Common point is Mikrotik, but rather Apple, but it will be very interesting to see what comes out here

Apple have a wired way of saving battery, including reducing power to wlan in sometimes no good way.

I see diffirent in your config and others is wmm
You should disable it. Will reduce battery life but connect always on

hi @all,
thank you for all the posts and ideas.
I wasn't active in this forum for some time but now I'm back

@sindy: Yes all the points you mentioned are correct.
Still have the earlier mentioned problem.
I'll do some more investigation because the customer is unhappy with all the disconnects....

Funny thing, with an AppRelease from February 2018 the Tillsystem- App is running better than with the newest ones...
But still looks like only happening with MT, not with other brands...

So the next days I'll do the wireshark sniff at the Master device's ethernet port and parallel sniff on MT.

Cheers