Access point not working

Unanswered Question
jaye15394 Fri, 03/21/2008 - 07:48

Are you referring to the windows error "limited or no connectivity?" If so, that means you aren't receiving an IP address from your DHCP server. If the switch you replaced was a Layer 3 switch, you will need to make sure you have the 'ip helper-address x.x.x.x,' configured where x.x.x.x is the IP address of your DHCP server.


interface vlan1 (the vlan the AP is in)

ip address

ip helper-address



It's already there. The only difference in the orginal (and then it was working) is the ip helper-addresses were the old servers and they are not longer on the network.

And the wireless network I'm troubleshooting, is for the public, therefore it doesn't have wpa keys. I'm new to wireless, so maybe I missing something. I will be at the branch having the trouble sometimes next week. Any advice you can give me on troubleshooting the switch and accesspoint connection would be greatlly appreciated. If I can supply any additional info, just ask.



jaye15394 Mon, 03/24/2008 - 05:58

Based on your description, it sounds like the problem is the client is not receiving an IP address. I would make sure the 'ip-helpers' are correct, a valid "Public" DHCP scope is created on the DHCP server, and verify the "Public" VLAN is tagged between the switches in the infrastructure.



jaye15394 Mon, 03/24/2008 - 10:43

Is the AP plugged directly into the switch with the 'ip helpers'?

The 'ip helpers' should be associated with an 'interface vlan xx.' Make sure the port the AP is plugged into is apart of that vlan. If the AP is serving multiple users (guests and employees, i.e. multiple vlans), then multiple vlans will need to be tagged on the link between the AP and switch and between any other switches that in the path down to the switch with the 'ip helpers' on it. The vlan tagging can be accomplished using dot1q trunking.

What kind of AP are you using? Autonmous or Lightweight?

Can you post the configuration of the switch with the 'helpers' and the switch the AP is plugged into?

jaye15394 Wed, 03/26/2008 - 19:09

It looks like port 24 is in desirable mode which will only negotiate a trunk if the other end is running DTP as well. I'm not sure on the AP running DTP. So please manually set port 24 to act as a trunk with these commands.

Try these on port 24:

switchport trunk encapsulation dot1q

switchport mode trunk

switchport trunk native vlan 1

Please rate if this helps.

thx..keep me posted.

craig.eyre Thu, 03/27/2008 - 10:43


I notice that all your vlan's are in the "shutdown" state, none of them will work while they are like that. You'll need to access the interface on the switch and perform a "no shut" to activate the interface.

If you need further assistance on this, let me know.


craig.eyre Wed, 04/02/2008 - 08:32

Hi Donna,

What model of switch and which IOS is it running?



craig.eyre Wed, 04/02/2008 - 08:42

Hi Donna,

Another question for you.

When you say everything else works fine, do you mean that the abbessidprivate and the abbessidpublic are working fine? Let me know.



It's a 3550 with version 12.2.

No, I'm not sure if any of the wireless is working. We only use the ABBEnet at that location. I'm going to make a trip out to that location sometimes this week. By everything else, I meant the switch. Not the access point. I just replaced the switch and it was working fine before and ABBEnet was working fine with the old switch.

Any advice would be great. Even advice on trouble shotting it once on location. We don't usually have trouble with ABBEnet. It's wide open, no keys or passwords. We have trouble with some of the keys on the other two wireless networks.

Before I came here they where having trouble with them because of the keys. We have cisco and bluesocket accesspoints and they can't use the same keys. Well, bluesocket doesn't support the longer keys. THis is my next project. And I really haven't worked with wireless before. Should be fun.

Let me know if you have any more questions.



craig.eyre Wed, 04/02/2008 - 11:22

what model of access point is connected to port 24 on the switch?


craig.eyre Wed, 04/02/2008 - 13:22

can you ping the new dhcp servers from the new 3550 switch?


Saurav Lodh Sat, 08/24/2013 - 01:07

It happens when IP is not received from dhcp, check the scope of dhcp.


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