topic Christian, in Wireless

Cisco WLC 2504 LAG Problem - Controller is shutting down when all four ports are connected

Christian Engelbrecht — Mon, 05 Jul 2021 12:52:57 GMT

Hi all,

I'm struggeling on a very strange phenomen.

One customer of mine is using a Cisco WLC 2504 controller (AirOS Version 8.2.100.0) connected to a HP switch (I don't know the type of model).

LAG is configured correctly as per configuration guide but it is only working as long as only two out of the four ports are connected.

As soon as port 3 and 4 are plugged in the WLC is not reacting anymore and reboots. There is nothing visible in the show msglog output or traplog output as well as there is no crashinfo available so it seems like a silent crash. However also when having a console cable connected to the WLC nothing is visible.

We have already replaced the WLC but without success.

Any ideas what could cause this?

Regards,

Christian

Christian,

Scott Fella — Tue, 27 Sep 2016 01:39:28 GMT

Christian,

I would really look at the switch configuration. I have a 2504 with LAG and used various code versions without any issue. The switch however is a Cisco switch. It is interesting that you can configure LAG and connect port 1 & 2, but when you connect port 3 or 4, the controller reboots. What happens if you try to connect the 2504 to another switch just for testing.

-Scott

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As soon as port 3 and 4 are

Leo Laohoo — Tue, 27 Sep 2016 03:00:38 GMT

As soon as port 3 and 4 are plugged in the WLC is not reacting anymore and reboots.

Sounds like a STP loop-forced crash. On the controller, post the complete output to the command "sh core summary".

Hi,

Christian Engelbrecht — Tue, 27 Sep 2016 06:28:10 GMT

Hi,

No crashinfo file is available at all. Coredump is enabled but nothing is transferred during the time the Controller faces the issue.

I'm getting a 2504 WLC today

Christian Engelbrecht — Tue, 27 Sep 2016 06:29:21 GMT

I'm getting a 2504 WLC today in MY office as well as some HP Switches. I have never faced such an issue before and I've many Setups that are working really good without any issues.

I will try to re-create the issue by today and will post MY results later.

Keep us posted.

Scott Fella — Tue, 27 Sep 2016 15:14:00 GMT

Keep us posted.

-Scott

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WLC2504 shutting down after port 3 or port is connected to PoE switch

bastone7 — Mon, 18 Dec 2017 23:48:24 GMT

Hi there,

were you able to resolve your issue, I'm also experiencing same but can't figure out what can be reason.

Re: WLC2504 shutting down after port 3 or port is connected to PoE switch

michael.wade — Mon, 26 Feb 2018 23:52:47 GMT

If anyone could offer some insight into this it would be greatly appreciated. I have a similar issue. When I plug into port 3 or 4 of the 2504 the controller it shuts down. When I unplug both, the power comes back on and the controller boots up. I'm running code 8.2.166 and the FUS is 2.0. The port channels are correct on my 2960-L switch, and still the same behavior. No misconfigurations on the layer 2 switch side. Like others, I have done this many times and the controller is new.

Re: WLC2504 shutting down after port 3 or port is connected to PoE switch

Vasco Costa — Thu, 26 Apr 2018 10:43:22 GMT

Any update on this issue?
A customer reported the same problem (2504 shuts down when he connects ports 3&4) but I've run out of 2504 to test this in my lab.

Have anyone test it by first desibling the PoE on the switch ports and then connecting the ports3&4?
Or force the speed and duplex config at both ends instead of leaving it as "auto"?

Re: WLC2504 shutting down after port 3 or port is connected to PoE switch

JordonH21 — Mon, 13 Aug 2018 17:35:31 GMT

I have the same issue with 8.2.166 version of code. I did try turning POE off on the ports but the controller still crashes when plugging into the POE ports (3 & 4)

Re: WLC2504 shutting down after port 3 or port is connected to PoE switch

Masato Ueoka — Tue, 14 Aug 2018 04:31:18 GMT

CT2504 8.2.166 with FUS 1.9
C2960L Gi0/1 -4 port-channel mode on.

What FUS version do you use?

Re: WLC2504 shutting down after port 3 or port is connected to PoE switch

Masato Ueoka — Tue, 14 Aug 2018 12:03:48 GMT

previous post is short.
In my lab , LAG works fine.
2504 8.2.166 FUS 1.9 and C2960L Gi0/1 -4 channel mode on

and 8.2 116 is deferred , pls use 8.2.170.

Re: WLC2504 shutting down after port 3 or port is connected to PoE switch

Vasco Costa — Fri, 17 Aug 2018 16:52:07 GMT

Are you guys trying making the LAG with stacked switches or does it happen when connecting to just one switch?

It happened again with a 4port lag to a 3 switch stack. 1 port connected to switch 1; 1 port connected on switch 2 and 2 ports connected on switch 3.

But, when we got all the 2500 on a single switch, all four ports were running whithout any problem.

Re: WLC2504 shutting down after port 3 or port is connected to PoE switch

dean.nash@va>gov — Thu, 31 Jan 2019 23:30:42 GMT

I have the same issue. I can LAG 1-3 fine but when adding port 4 to the channel, the WLC drops and reboots. Cannot believe there is no solution for this behavior.

ANAKIN#sho int status | i WLC
Gi2/45 WLC LAG connected trunk a-full a-1000 10/100/1000-TX
Gi2/46 WLC LAG connected trunk a-full a-1000 10/100/1000-TX
Gi3/45 WLC LAG notconnect 1 auto auto 10/100/1000-TX
Gi3/46 WLC LAG connected trunk a-full a-1000 10/100/1000-TX
Po50 DOWNLINK to WLC connected trunk a-full a-1000
ANAKIN#sho ehterc 50 sum
^
% Invalid input detected at '^' marker.

ANAKIN#sho etherc 50 sum
Flags: D - down P - bundled in port-channel
I - stand-alone s - suspended
H - Hot-standby (LACP only)
R - Layer3 S - Layer2
U - in use f - failed to allocate aggregator

M - not in use, minimum links not met
u - unsuitable for bundling
w - waiting to be aggregated
d - default port

Number of channel-groups in use: 2
Number of aggregators: 2

Group Port-channel Protocol Ports
------+-------------+-----------+-----------------------------------------------
50 Po50(SU) - Gi2/45(P) Gi2/46(P) Gi3/45(D) Gi3/46(P)

ANAKIN#sho run int po50
Building configuration...

Current configuration : 223 bytes
!
interface Port-channel50
description DOWNLINK to WLC
switchport
switchport trunk encapsulation dot1q
switchport trunk native vlan 1000
switchport trunk allowed vlan 7,10,40,50,90,100,1000
switchport mode trunk
end

ANAKIN#sho run int g2/45
Building configuration...

Current configuration : 234 bytes
!
interface GigabitEthernet2/45
description WLC LAG
switchport trunk encapsulation dot1q
switchport trunk native vlan 1000
switchport trunk allowed vlan 7,10,40,50,90,100,1000
switchport mode trunk
channel-group 50 mode on
end

(Cisco Controller) >show sysinfo

Manufacturer's Name.............................. Cisco Systems Inc.
Product Name..................................... Cisco Controller
Product Version.................................. 8.5.135.0
Bootloader Version............................... 1.0.20
Field Recovery Image Version..................... 7.6.101.1
Firmware Version................................. PIC 16.0

Re: WLC2504 shutting down after port 3 or port is connected to PoE switch

dean.nash@va>gov — Fri, 01 Feb 2019 16:02:21 GMT

Just tested moving a working LAG connection (ports 1-3) from port 3 on the controller to port 4 and it comes up fine. This indicates to me that there is an issue with the controller when adding the 4th LAG connection with 2 connections to each blade. Moved all 4 connections to the same blade and all 4 come up. It appears that someone decided that the 2504 should not have full redundancy in the LAG for some odd reason. Have yet to try a 3 and 1 configuration to see if it will work but I have little hope.

Re: WLC2504 shutting down after port 3 or port is connected to PoE switch

Mikey Boy — Fri, 01 Feb 2019 16:18:32 GMT

The WLC 2504 will only support 1Gb throughput regardless of the LAG configuration, so is there really any point in up linking 4 ports?

Also, a stipulation is that the bundled ports must not be on different switches in a stack, they must be on the same switch.

https://www.cisco.com/c/en/us/support/docs/wireless/2500-series-wireless-controllers/113034-2500-deploy-guide-00.html#anc24

Re: WLC2504 shutting down after port 3 or port is connected to PoE switch

dean.nash@va>gov — Fri, 01 Feb 2019 16:19:16 GMT

Wow.... What a jacked up device! 4 Port LAG worked with ports 2-4 on blade 2 and port 1 on blade 3. For giggles, I tried putting ports 1 and 3 on bade 2 and 2 and 4 on blade 3, no joy. Put ports 1 and 2 on blade 3 and 4 on blade 2 and up she comes like a dream. I'm a little OCD so I wanted 1&2 on blade 2 and 3&4 on blade 3. Guess what? No workie. WTH? Who makes something like this?????

Re: WLC2504 shutting down after port 3 or port is connected to PoE switch

dean.nash@va>gov — Fri, 01 Feb 2019 16:23:29 GMT

Understand, but is not the point of LAG here redundancy? Requiring all the LAG ports to be on the same switch kinda defeats the point, yes?

Re: WLC2504 shutting down after port 3 or port is connected to PoE switch

Mikey Boy — Fri, 01 Feb 2019 16:30:46 GMT

It is definitely one of the quirks that came with the 2504 but it has been end of lifed. I never really classed it as a device for larger mission critical deployments tbh. The 3504 is better and has replaced it from this perspective.

From a redundancy point of view we have always supplied 2 2504's that way you just lag the second one into a different switch.......

Re: WLC2504 shutting down after port 3 or port 4 is connected to PoE switch

michael.wade — Fri, 01 Feb 2019 17:11:36 GMT

I apologize for waiting almost a year to post a follow up. I did resolve this, and had it happen a few times again when doing a factory reset on the 2504. Certainly isn't a fix in my opinion, but it worked every time. Connected to ports 1 and 2 then In the GUI, click Controller - then Ports. Then "ConfigureAll" in the upper right hand corner. Changed the Admin Status to "Disable" then Applied. Immediately went back and changed the Admin Status to "Enable", then Applied. Then I was able to plug in ports 3 and 4 and have been good since running on all 4 ports.

When I posted back in 2018, I was enabling/disabling every individual port but that never worked. Just sharing my experience as this may not apply to other's.