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New Member

2106 not able to trunk

Dear All,

I am seeing a strange issue with WLC 2106. Following is my setup :

Catalyst 3750 <-> WLC 2106 <-> 1131 AP

I have a physical port on 3750 configured as dot1q trunk. I have allowed all the VLANs. On 2106, I have the default interfaces configured with IP addresses. Everything is fine up to this point. When I create a dynamic interface on 2106 I lose the connectivity to my managment interface along with the AP-manager interface. However, I can ping the Dynamic interface which I created but it doesn't let me manage the controller. I believe that you can configure the dynamic interface to allow the management of controller. I don't know if this is a known bug or not but if I delete the dynamic interface I am able to restore the connectivity to the management interface.

While creating the dynamic interface for WLAN I specify it to be on the same physical port as managment which is port 1. I don't want to have two phyical links from the controller to the switch so I haven't tried to isolate the dynamic interface to point to one of the other physical interfaces. Also, this will not work if I have more than 6 vlans.

Any help is much appreciated.


Cisco Employee

Re: 2106 not able to trunk

Hi Friend,

Can you please paste me the output of "sh interface sum" from controller console port after you configure dynamic interface. As you said you will loose the connectivity but console will give you an access. Also paste the output of "sh interface switchport" from 3750 switch which is connected to this controller?

Can you confirm which version of code you are running on your controller?



New Member

Re: 2106 not able to trunk


I have the same problem here. As soon as I add another interface to the 2106, I lose connection to the management interface. I have tried adding the new interface to a different port but i still lose connectivity to the management interface that is on port 1. We are in a hurry to get this unit running as it is on trial from our vendor. Has anyone got a solution for this?

Interface summary after adding the interface:

(Cisco Controller) >show interface sum

Interface Name Port Vlan Id IP Address Type Ap M


-------------------------------- ---- -------- --------------- ------- ----


ap-manager 1 untagged Static Yes

management 1 untagged Static No

virtual N/A N/A Static No

vlan1 1 1 Dynamic No

Cisco Employee

Re: 2106 not able to trunk

Hi Friend,

Which vlan you have defined on your switch trunk as native vlan? By default it is vlan 1 on switches. And I see that you have configured your dynamic interface with vlan 1 so if native vlan is default on switch its a problem.



New Member

Re: 2106 not able to trunk

I spoke to Cisco TAC. As per them you can't mix wired & wireless clients on the same vlan. I do have an existing wireless infrastructure & a separate wireless vlan so it didn't make sense in my case. TAC engineer's next thought was, in my case, since I already have a wireless infratructure & I am trying to use the same vlan which I used with autonomous APs might be causing this problem. All the configs were verified.

I was adivsed to wait for 4.2 release.

Has anyone else seen this issue before?

New Member

Re: 2106 not able to trunk

You absolutely should be able to accomplish this. We use 2106's quite a bit and always attach them via one trunk port onto the wired network.

When you create this dynamic interface, are you setting its own VLAN ID? You will have a problem if you try to create a dynamic interface with the same VLAN as the AP-Manager or Management interface.

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