WLC 2504 FlexConnect not getting IP address.

[sardarjion]

I have 2504 WLC v8.5.182.0 with two 2702i connected to it. The router is RVS 4000 and has 4 VLANs where VLAN ID 4 is assigned to FlexConnect. 1 is for management, 2 and 3 are for iot and guest. 

Router assigns the IP address as 192.168.X.100-192.168.X.200/255.255.255.0 and Gateway is 192.168.X.1 where X is VLAN ID.

In the WLAN section, if I don't enable the option "FlexConnect Local Switching" then everything works fine. I am able to connect and get the IP address on client (iPhone 13) and browse internet. 

If I enable the option "FlexConnect Local Switching" then I see iPhone trying to connect to wifi but is never successful. I enabled DHCP logging but I don't see any activity in the failure case. I am not sure what logging I should enable to debug this further. 

[marce1000]

  - I would suggest to perform client debugging , these can be analyzed with : https://cway.cisco.com/wireless-debug-analyzer/

 M.

[Scott Fella · Accepted solution]

What is the switch the ap's are connected to?  If the ap's are connected to the 2504, that will not work.  You need to have a switch that you can configure a trunk if you want to have multiple vlans for wireless.  AP's connected directly to the 2504 will only have access to the management vlan.

[sardarjion]

Hi Scott,

You nailed the problem. Since this was homelab setup, I had the main test AP connected to POE port 3 of WLC 2504 and it wasn't working. I removed the AP from WLC and was able to get the IP and data flow going.

Would you know why this problem happens in FlexConnect mode? The WLANs which are not configured as flexconnect and in local work fine when AP is connected to WLC poe port. Even different VLANs work fine in local mode. 

[Rich R]

> Would you know why this problem happens in FlexConnect mode?
By design: https://www.cisco.com/c/en/us/td/docs/wireless/controller/2500/quick/guide/ctr2504-qs.html#pgfId-1405414
"directly connected local mode APs via two PoE (Power over Ethernet) ports are supported."

[sardarjion]

Hi Rich,

Thanks for the reply. From the link shared, it says "With Release 7.4, directly connected local mode APs via two PoE (Power over Ethernet) ports are supported. Directly connected APs were not supported before Release 7.4.".

I am just wondering why were the POE ports put to begin with when it cannot be used to power and connect AP. 

[Rich R]

It CAN be used to power and connect an AP but only in local mode not flexconnect mode.