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Catalyst 3550 POE conflict with 3Com 3102 phones (PLEASE HELP)


We have a Catalyst 3550 with 6 3Com 3102 POE phones attached to it without being able to be powered on using POE. According to 3Com, the 3102 models work under a different voltage than the Cisco phones but the 3550's should be able to pick up the voltage automaticaly. My question is: Is there a way to set the voltage to the POE ports or is there another way we can resolve this issue without having to plug power adapters to the phones? Thank you.

4 Replies 4


What does the "show power inline " command show you ?

Leo Laohoo
VIP Community Legend VIP Community Legend
VIP Community Legend

Depends on the IOS ... You can use a variety of commands on the interface-level.

power inline consumption

power inline auto

power inline auto max

power in static max

Check to make sure that "no power in never" is present.

You may want to try with the "power inline auto" first and compare the results.

Sushil Kumar Katre
Rising star
Rising star

Hi Wagner ,

If I can recall correctly, 3550 switch supports Cisco Prestandard PoE and not 802.3af. I guess that should be the issue. Try connecting them to other 802.3af supported switch if you have any (3560/3750).

-> Sushil

Here's the Q&A which talks about this -

Q. Does the Cisco Catalyst 3550-24 PWR Switch support the 802.3af inline power standard?

A. No, this switch supports Cisco Pre-Standard Power over Ethernet. The Catalyst 3750 Series and Catalyst 3560 Series support the Cisco Pre-Standard Power over Ethernet and IEEE 802.3af Power over Ethernet.

-> Sushil

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