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PoE with Cisco WAP121 & Cisco AIR-PWRINJ3 not working


I bought a Cisco WAP121 and a Cisco AIR-PWRINJ3 so I could use the PoE from the AIR-PWRINJ3 to power the WAP121.  Unfortunately the setup is not working, the WAP121 shows no sign of getting power even though the AIR-PWRINJ3 indicates it has power.  Is this setup just not supported or do I have defective parts?

5 Replies 5

Leo Laohoo
VIP Community Legend VIP Community Legend
VIP Community Legend

Could be you have a faulty cable.

I tried my own Cat5e cable and the cable that came with it.  No go on either.

Hello Craig,

I believe you are using the wrong power injector with this AP. According to the datasheet the power injector SKU is

SB-PWR-INJ1-xx, where XX would indicate your region(ie for North America it is NA). Here is the link to the datasheet:



Wow, I looked all over for that part in the documentation but did not see it. 

Than again, all the WAP121 documentation says it just needs PoE, it doesn't say you have to use that one.  Is the AIR-PWRINJ3 not a true PoE power injector?

Hello Craig,

It is my understanding the AIR-PWRINJ3 is not 802.3af compatible, but rather compatible with the Cisco pre-standard POE. This is why it works with the phones and other Cisco APs which support that version of POE, but not the WAP121 which is only 802.3af POE capable only.



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