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Aironet 1140 not connecting to network when on PoE

I have an Aironet 1140 AP that will not connect to the network when on PoE (either using a Cisco PoE injector) or a Avocent Switch that provides PoE.

The AP will boot up and and devices will connect to it (the LED changes to blue) but none of the devices can get access to the corporate network or internet.

When the AP is powered by the standard power supply, it operates normally, i.e. devices can access the network.

Are there settings that can be changed to get the AP to work correctly on PoE?

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Hall of Fame Super Gold

Aironet 1140 not connecting to network when on PoE

I have an Aironet 1140 AP that will not connect to the network when on PoE (either using a Cisco PoE injector) or a Avocent Switch that provides PoE.

This is a wierd problem.

Let me get this straight:  If the WAP is powered using an Avocent switch users are able to JOIN the WAP but can't access the network?

If the WAP is powered using a Power Injector, users are able to join the WAP but can't access the network.

If the WAP is powered using a power supply, users are able to join the WAP and can access the network.

When you mean "can't access the network", do users get valid IP addresses?  

Are you using the SAME CABLE to connect the WAP to the network when using the PoE/Injector and the power supply?

New Member

Re: Aironet 1140 not connecting to network when on PoE

If the WAP is powered using an Avocent switch users are able to JOIN the WAP but can't access the network? CORRECT  

If the WAP is powered using a Power Injector, users are able to join the WAP but can't access the network. CORRECT  

If the WAP is powered using a power supply, users are able to join the WAP and can access the network. CORRECT 

When you mean "can't access the network", do users get valid IP addresses?  THEY DON'T GET AN IP ADDRESS  

Are you using the SAME CABLE to connect the WAP to the network when using the PoE/Injector and the power supply? YES THE SAME CABLES ARE BEING USED. I ALSO TRIED BRAND NEW CABLES

I also should have mentioned in my original post that I can't access the AP via web browser or telnet or ping it when its connected via PoE Switch or Injector

Message was edited by: Peter Johnston (corrected formatting)

Hall of Fame Super Gold

Aironet 1140 not connecting to network when on PoE

If the WAP is powered using an Avocent switch users are able to JOIN the WAP but can't access the network? CORRECT

If the WAP is powered using a Power Injector, users are able to join the WAP but can't access the network. CORRECT

If the WAP is powered using a power supply, users are able to join the WAP and can access the network. CORRECT

I have a stupid feeling in my stomach I know what this is all about.  Power injectors and PoE power the WAP using the 3rd pair in an ethernet cable.  However, the first and second pair are the important bits as well.  If either (or both) pairs A and B are not terminated properly, the WAP powers up and that's about it.

I know you've said you've replace the cable but I can assure you this bit of information unsettles me.  This is because I've deployed over 1000 WAPs, using PoE and injectors, which means I also took hold of > 3000 patch cables direct from the manufacturer.  Let me tell you that I have around 9% failure rates of these cables.

How do I know?  It's because the switches I've deployed, Cisco 3750 and 2960/2960S, have TDR and I've tested cables which are giving me issues.

My recommendation is this:  Get the cables tested by a reputable TDR tester like a Fluke DTX1800.  Alternatively, if you have a Cisco 3560G/E/X or 3750G/E/X or 2960G/S then you can do that also.

Just want to give you a warning that some so-called TDR machines will only test the first two pairs of cables and will not be able to test all four pairs. 

Bronze

Re: Aironet 1140 not connecting to network when on PoE

Hi,

On this access points we need to specifc how the unit is getting power either from a POE switch or power injector becasue if not the unit will be able to power on but not enable the radios.

If you use the AC adapter it is not required to confiugre anything.

You can configure how the access point is getting power by accesing the GUI of the Ap and then click on system software, system configuration.

Also make sure that the POE switch is 8023af and can support up to 15 via POE since this AP needs this power to be able to enable both radios and that the power inejctor being used is (AIR-PWRINJ4=)

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