MikroTik SXTsq Lite2 attached to a CPE510 2nd PoE port weird problem

I have a MikroTik SXTsq Lite2 with Openwrt plugged to the 2nd PoE port of a CPE510 v1 with tp-link firmware.

When I reboot the Mikrotik FROM Luci, I cannot ping it and it does not go up, although I see the port up in the CPE.

If I disable PoE Passthrough: and enable back in the CPE, same behavior.

Only way to get the Mikrotik back up is to reboot the CPE510, then it gets alive.

I am pulling my hair trying to understand whats is going on. Before I had a CPE210 with openwrt there and no problems at all.

Tks for ur ideas.

I've checked the device and it does not boot, at least with Openwrt. The wifi it radiates is missing until the CPE510 feeding it is restarted.

No one?


well you should check tplink setting, this is not about openwrt.
sxtsq have a static ip or it get dhcp?

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I am not playing the blame game :slight_smile: just trying to understand what is going on in the SXT cos before I had a CPE210 with openwrt there and this did not happen.

Could it be some failsafe thing? There is some preboot that hangs waiting for something?

Tks, appreciated

Indeed the CPE510 is to blame cos I have another SXT plugged to the 2nd PoE port of a Nanostation 5ac and the Mikrotik with openwrt boots smoothly after I restart the PoE passtrought in the nanostation.

The failed boot is likely caused by an insufficient power. Check if it hangs or it goes into a bootloop. The part with rebooting the CPE510 is interesting - Was the WiFi UP while the Mikrotik was booting?
The PoE Passthrough is controlled by a GPIO, so it has only two states and cannot be OS related, therefore.

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It hangs, cos when you watch the 2nd port status in the CPE510 it stays on fixed. When it is a bootloop you can see online-disconnected there.

Yes, the wifi in the Mikrotik is always up, but when you try to restart from Luci or switching off/on PoE passtrought in the CPE, the wireless network is never aired and you cannot ping the device.

Just rebooting the CPE510 you can see it back.

My question was about the WiFi on the CPE510 - It increases the power consumption. Possibly it goes to ACS/DFS on reboot, so using less power.
Another option is the Mikrotik trying to boot over the LAN for some reason or receiving some "crafted" packet which is unlikely.

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Yes it was, as maxstream (Tp Link TDMA) wireless client.

So does the Mikrotik boot normally with WiFi disabled on the CPE510?

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Hard to test cos I do it remotely.
If I disable wifi in the CPE I will lose access to the routers.They are in a camping.
I will be onsite tomorrow and will give it a try.
Will let you know.

I would ssh to the CPE to sniff what is going on while the SXT is hanged, but that tp-link crap almost has no tools for checking!

Tks again.

Checking specs I see the CPE210 that was there before has a 10,5W max power consumption while the Mikrotik says 5W.

I remember I had a Ligowave (Deliberant) in the 2nd port of a CPE510 and experienced power issues until I set a 100MB half speed in the Ligo.

If it's a power issue, you may try some script if boots without wifi or increasing the voltage. The cable itself has some resistance, possibly limiting the current. For CPE510 is also stated 10.5 Watts Max, 16-27VDC, not including the cable losses.