WLC 2504 Internal DHCP Server won´t give IP addresses to wifi clients

[antoniocatalan]

Hello everybody, this is my first post in this great forum that has helped me many times in the past. Now a dire situation made me to get help for the first time.

This is the scenario: Started configuring  WLC 2504 and 4 APs (LAP-1602i) last week.. Managed to configure the wlc 2540 internal DHCP server and the APs are getting IP addresses succesfully. Pool Address is (10.0.0.10 - 10.0.0.250). Issue is the following: all wifi clients trying to connect to the SSID never gets IP addresses but they appear as connectd clients in the wlc client status list. note: All wifi clients are getting APIPA address (169.x.x.x)

so, Why are the APs getting IPs successfully from the wlc internal DHCP Server but not the clients trying to connect through them? 

What am i doing wrong? Thanks and sorry for my english.

[Rasika Nayanajith · Accepted solution]

Hi 

Welcome to the CSC forum :)

What is the DHCP server configured under the dynamic interface defined for the wlan.

It should be WLC management IP address. Check that & I think that may be the problem

HTH

Rasika

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[antoniocatalan]

Thank you for the quick answer! I checked the WLAN configuration for a DHCP override with the management interface IP configured. Also, within CONTROLLER-Interfaces options, got the same management interface IP. I will check both options separately and together.

[antoniocatalan]

It seems is now working! both the DHCP override option with the configured IP and the DHCP primary server also configured is what I tested.

Now a new issue: It gets too slow when connecting wifi clients....aprox 20 seconds till they successfuly connect and get IP from the wlc internal DHCP. This is a test scenario im working on so this is the case: WLC 2504 - SWITCH - APs , with no other stuff in the middle. Is there any way i can speed up this process? Thanks!

[Rasika Nayanajith]

WLC is not the best place to run DHCP server functionality. specially in large scale deployments.

Prefer if you can move the DHCP server functionality to the switch if that is a possibility.

HTH

Rasika

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[antoniocatalan]

WLC DHCP Server will be used for 4 APs and delivering IPs for aprox. 60 wifi clients. Do you consider this a large scale deployment? The Pros of this internal DHCP server si that is exclusively for wifi clients and no wired clients can get IPs from it. Scenario case is of a flat class C network with other DHCP Server already installed for other purposes. Thanks!

[Rasika Nayanajith]

This is not a large scale deployment.

If you want to test & see the difference you can create DHCP pool either on your DHCP server or WLC connected switch.

It does not make sense defining DHCP at different places if you have a proper DHCP server. (typically WLC DHCP use for guest services where WLC placed in a DMZ where no direct connection with other corporate services & from security perspective you do not won't to mix these traffic with your corporate traffic)

HTH

Rasika

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