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New Member

Light weight AP not keeping its dhcp address.

Hi,

I'm currently having an issue whereby a light weight ap is not able to keep its dhcp address for long. Firstly I will power cycle the port with a shut, no shut and monitor the port and it will receive a dhcp address and be pingable for a while and then drop off completely. I've tried to power cycle this many time and the same result. I know there shouldnt be a problem with the configuration on the edge switch or core sore level as same edge switch has another AP that is connected to the WLC fine.

Here are my edge switch port config:

         

interface GigabitEthernet0/8

description "Wireless AP - AP_12"

switchport trunk encapsulation dot1q

switchport trunk native vlan 500

switchport trunk allowed vlan 460,500,600,605,610

switchport mode trunk

Here is the show cdp neighbour output:

SW_07#show cdp neighbors detail

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

Device ID: AP_12

Entry address(es):

  IP address: 10.236.10.101

Platform: cisco AIR-LAP1142N-N-K9   ,  Capabilities: Trans-Bridge

Interface: GigabitEthernet0/8,  Port ID (outgoing port): GigabitEthernet0

Holdtime : 166 sec

Version :

Cisco IOS Software, C1140 Software (C1140-K9W8-M), Version 12.4(23c)JA7, RELEASE SOFTWARE (fc1)

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 1986-2013 by Cisco Systems, Inc.

Compiled Tue 29-Jan-13 05:08 by prod_rel_team

advertisement version: 2

Duplex: full

Power drawn: 14.500 Watts

Power request id: 11530, Power management id: 0

Power request levels are:15400 14500 0 0 0

Power Available TLV:

The AP firmware is 12.4 which shouldnt be an issue with downloading its firmware from WISM cards.

I don't understand why its not keeping IP connectivity. These are configured as HREAP access points so consoling to the AP is not a viable option.

Please help.

Cha

6 REPLIES
VIP Purple

Light weight AP not keeping its dhcp address.

Hi Wilton,

This mean your AP cannot find WLC to register & going through  the reboot process to find a WLC. If you configured DHCP on a IOS device (like a switch) every time it will give a new IP unless you reserved an IP to AP mac address.

To fix this you need to get AP console output to see what's going on or at least configre HA (Primary Controller) for this AP.

HTH

Rasika

**** Pls rate all useful responses ****

VIP Purple

Light weight AP not keeping its dhcp address.

Hi wilton,

Agree with Rasika.

What you can do is, once AP gets IP from DHCP server, you can change to Static IP. After this you will not loose IP addres.

If you still having this issue then paste the logs from console of AP.

Regards

Dont forget to rate helpful posts

Hall of Fame Super Silver

Re: Light weight AP not keeping its dhcp address.

Has this AP joined the WLC before or is this new? Was it working fine, did you move this AP from another site?

Anyways, if this AP doesn't join, you only real option is to console into the AP and post the output so we can see what is really going on.

Sent from Cisco Technical Support iPhone App

-Scott
*** Please rate helpful posts ***
New Member

Light weight AP not keeping its dhcp address.

Yes this AP has joined a controller before. I was moving AP groups from one controller to another. I had changed the switch dhcp scope and referenced the new option 43 hex code and then did the transition to the new controller. All AP's in this group except this one was successull.

Thanks for everyones help. I may try assigning it a static IP first and if that fails get someone to provide me console output.

Cheers

Wil

Hall of Fame Super Silver

Re: Light weight AP not keeping its dhcp address.

Something could of went wrong. You should remove the DHCP option and try using an IP helper on the AP subnet and globally on the router, IP forward protocol UDP 5246 and IP forward protocol UDP 5247

Then power cycle the AP by shutting down the PoE port.

You can also try to create a DNS entry Cisco-capwap-controller. and point that to the WLC management IP.


Sent from Cisco Technical Support iPhone App

-Scott
*** Please rate helpful posts ***
New Member

Light weight AP not keeping its dhcp address.

Thanks for the quick response. Will do that sometime today and let you know how it goes.

Thankyou

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