C9800 Mgmt via Wireless not working when clients in same subnet

[Tobias Heisele]

Hi all,

I have a "not so common" setup Flexconnect design of multiple sites, one subnet each. On the HQ, WLC is in the local subnet aswell, but still using Flexconnect (for the ease of use). "Management over wireless" is enabled and is working from all sites except HQ. Here the clients are not even able to ping the WLC. Wired clients can reach the WLC. I suppose this is some kind of expected behaviour, but can someone explain the root cause for this?

[MHM Cisco World]

When you use flex Mode' AP have vlan different than vlan in wlc.

Indeed we push config of vlan to flex AP but wlc dont have interface in these vlan'

So client use IP in subnet not known by wlc that make traffic drop.

Above true if you use WAN between wlc and AP

MHM

[MyHomeNWLab · Accepted solution]

> C9800 Mgmt via Wireless not working when clients in same subnet

Could this possibly meet the conditions of the following issue?

CSCvu29200: mgmt-via-wireless not working if client has IP from wireless mgmt vlan [ Flex local switching ]
https://bst.cisco.com/bugsearch/bug/CSCvu29200
> Symptom:
> Flexconnect local switching wireless client will not be able to ping / ssh / https to the wireless controller if it has an ip from the controller's wireless management interface. If it gets an IP from another interface, everything works fine
>
> Conditions:
> Flexconnect / local switching
> Client has IP from wireless management VLAN
>
> Workaround:
> use wired device or wireless client from another vlan to manage WLC
>
> Further Problem Description:

[MHM Cisco World]

Sure it can 

Check ipconfig of wifi client abd check IP it is in same subnet of wmi of wlc or not

MHM

[MyHomeNWLab]

FYI
I investigated the detailed conditions for CSCvu29200.

The condition for CSCvu29200 is strictly the VLAN ID match rather than the subnet.
Therefore, communication is possible when the Native VLAN ID is on the same subnet as WMI.

[ Example ]
* Flex Profile's Native VLAN ID: 1 (Untagged)
* Policy Profile's VLAN ID: 1
  Belongs to subnet: 192.168.0.0/24

* WMI VLAN ID: e.g. 123
  WMI's IP Address: 192.168.0.123/24

[Tobias Heisele]

Thank you very much @MyHomeNWLab, this is exacly the case in my setup.