topic Re: Client NO IP on WLC 9800 Flex Connect AP setup in Wireless

Client NO IP on WLC 9800 Flex Connect AP setup

Ruelb2214 — Wed, 21 Feb 2024 03:41:06 GMT

Hi All,

I don't know if anyone has similar issue with my setup, client not able to get IP upon checking on the Wireshark, it's not able to discover the DHCP server. WLAN and Policies, Site properties and RF properties are setup correctly, created VLAN in WLC.

I'm using WLC 9800 version 17.9.4a with 9120AXI AP

On the switch I created the interface VLAN for User subnet and with ip helper pointing to DHCP server, but still don't work. Hope someone here can give some lights.

I have followed this guide also to make sure all settings are correct.

Understand FlexConnect on Catalyst 9800 Wireless Controller - Cisco

Re: Client NO IP on WLC 9800 Flex Connect AP setup

Mark Elsen — Wed, 21 Feb 2024 07:12:23 GMT

- Have a checkup of the WLC 9800 configuration with the CLI command show tech wireless and feed the output into :
Wireless Config Analyzer

- Use client debugging according to : https://logadvisor.cisco.com/logadvisor/wireless/9800/9800ClientConnectivity
The so called RadioActive Traces (client debugs) can be high level analyzed with : Wireless Debug Analyzer

Re: Client NO IP on WLC 9800 Flex Connect AP setup

Rich R — Wed, 21 Feb 2024 16:00:28 GMT

> created VLAN in WLC
Flexconnect local switching does not require VLAN definition on the WLC! You can define the VLAN in the flex profile or simply enter the VLAN number (ID) in the policy profile for the WLAN.

Have you configured the WLAN for local switching and disabled central DHCP?
And you're sure the AP is in Flexconnect mode? "no local-site" in the AP site tag.
Does a PC plugged into the same VLAN on the switch work correctly?

Have you configured the AP port as trunk port and allowed the client VLAN on that trunk port?

Without more detailed information on your WLC, WLAN and switch configuration it's really difficult to offer any more help than that.

Re: Client NO IP on WLC 9800 Flex Connect AP setup

Ruelb2214 — Thu, 22 Feb 2024 06:20:52 GMT

Hi @Rich R to answer your questions

Have you configured the WLAN for local switching and disabled central DHCP? YES (pls see attached)

And you're sure the AP is in Flexconnect mode? "no local-site" in the AP site tag? YES (pls see attached)

Does a PC plugged into the same VLAN on the switch work correctly? YES tested and able to get IP Address

Have you configured the AP port as trunk port and allowed the client VLAN on that trunk port? YES

interface GigabitEthernet1/0/40
description AP_e4a4.1cac.faac
switchport trunk native vlan 14
switchport trunk allowed vlan 14,20
switchport mode trunk

VLAN14- management AP

VLAN20-User Wireless

Re: Client NO IP on WLC 9800 Flex Connect AP setup

Ric Beeching (Cisco) — Thu, 22 Feb 2024 06:33:52 GMT

Have you created the VLAN in the flex profile? This makes the AP aware of the VLANs and uses them for bridging traffic to the wire.

https://www.cisco.com/c/en/us/support/docs/wireless/catalyst-9800-series-wireless-controllers/213945-understand-flexconnect-on-9800-wireless.html#toc-hId-2014319370

Re: Client NO IP on WLC 9800 Flex Connect AP setup

Rich R — Fri, 23 Feb 2024 09:55:30 GMT

VLAN                                : VLAN20

You've used a named VLAN therefore you must define the VLAN in the flex profile - have you done that?
Otherwise you need to use the VLAN ID (number) - 20 - in the policy profile.
The AP has no way of knowing what VLAN20 means if you don't define it.
This is what I already said in my previous reply and what @Ric Beeching (Cisco) said too.

Re: Client NO IP on WLC 9800 Flex Connect AP setup

Ruelb2214 — Tue, 27 Feb 2024 07:12:19 GMT

Hi All,

Thanks for your time to reply on my query. I was able to solve the issue, I was confused with the setting vlan, after putting correct VLAN ID, client able to connect.

Re: Client NO IP on WLC 9800 Flex Connect AP setup

Rich R — Tue, 27 Feb 2024 09:08:49 GMT

You're welcome - glad to hear you worked it out <smile>