Meraki AP MR57 Randomly Restarts

[fdharmawan]

Hi Guys, anyone using MR57 on their deployment? Currently I am experiencing an issue where random APs went to a self restart. I checked on the AP and switch end, nothing suspicious. On the switch side, the log only shows up/down on the interface of the AP. On the AP side, this is the log.

And the AP uptime is reset, meaning that the AP really went on a restart.

Currently the AP is running MR 30.7. The occurrence of the issue is random, sometimes in the middle of the night. Anyone experiencing the same with your MR57? Thank you.

[VivekT]

Hello,

I do have MR57 running on same firmware , my APs are stable since 90 days. Is it happening for all APs connected on same switch?

[fdharmawan]

Hi Vivek,

Are you using 1 or 2 LAN connection? The issue happened to around 40s of total 120s AP in my deployment. Everyday different AP experiencing the issue.

[rwiesmann]

I would try to exclude as many points as possible

• Change the switchport
• If possible on a switch port on an other switch

With that you can exclude the switch

• Then change cables

With that you can exclude the cables 

If then the problem still exists, i would open a support case with cisco.

[fdharmawan]

Hi rwiesmann,

• Change the switchport -> Okay will try this. Currently happens to many APs across different switches.
• If possible on a switch port on an other switch -> I think we can exclude this as happened to different switches already.
• Then change cables -> The cables are newly installed. Passed the fluke test as well.
• i would open a support case with cisco -> Will try this as well

[TyShawn]

What switch do you have running these APs? Also, how are they being powered?

[fdharmawan]

Hi TyShawn,

The current switch is Cisco 3850. Planning to replace the switch with Meraki 9300M in the next few months. They are powered through PoE.

[Rob2041]

Did this start randomly, or after you added MR57s?  Does the switch have any power saving options enabled where it would shut down devices? Are you running out of POE budget on the switch?  

[fdharmawan]

Hi Rob,

This starts after I added MR57s. Previously with Cisco 3802, I did not get issue like this.

Does the switch have any power saving options enabled where it would shut down devices? -> May I know how to check this?

Are you running out of POE budget on the switch? -> Nope, only 10-15% of the total power budget are consumed.

[Rob2041]

3850 switches probably won't have the power saving mode.

however, are they poe+ or UPOE 3850's are the AP's showing they are pulling the full 30 watts?

is CDP enabled?

Is the IOS on the 3850's somewhat updated? I've seen 3850's do strange things depending on the IOS or hardware version, I also would not update if super far behind and you have no spares. 

are the MR57's in the portal showing low power mode?

I would also see if you can pull any events from the switch(s).

[fdharmawan]

Hi Rob,

however, are they poe+ or UPOE 3850's are the AP's showing they are pulling the full 30 watts? -> Yeap, in fact they are pulling 47.2W for each APs.

is CDP enabled? -> CDP and LLDP are enabled

Is the IOS on the 3850's somewhat updated? -> I am running 16.12.10a for all of my switches. The latest recommended version is 16.12.12, so not far behind.

are the MR57's in the portal showing low power mode? -> Nope, no warning on the portal.

I would also see if you can pull any events from the switch(s). -> Below are the logs on the related to the corresponding port. 

[IvanJukic]

"47.2W for each APs." 40Watts is the Maximum for the MR57. Did you mean 47.2 Volts?
https://documentation.meraki.com/MR/MR_Overview_and_Specifications/MR57_Datasheet#Specifications

Judging from that Screenshot; perhaps Spanning Tree could be shutting ports??? That would make sense if configured in 'Power Sharing' mode'. 

As you have an Agg/Port Channel configured. Make sure it is configured correctly and matching on both the switch and MR57. See below details.

https://documentation.meraki.com/MR/MR_Overview_and_Specifications/MR57_Dual_Uplink_High_Availabilit...

[fdharmawan]

Hi Ivan,

Nope, it's 47.2W. Please find the sample output below. Is this normal? I mean, the AP is overconsuming above than the stated wattage on the device manual?

I do not think spanning tree is shutting ports, since the port is not disabled. Only the device is going down the up again. I have checked, my switch is configured in power sharing.

I only connect 1 LAN into the MR57 AP. So I do not have aggregation towards the AP in my deployment.