Catalyst 3750 V2 and PoE

Unanswered Question
Jan 14th, 2010
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I've got a stack of 2 new Catalyst 3750 V2 48 ports PoE.All the ports are configured to support ip phones + pc (switchport access vlan X + switchport voice vlan Y)

My problem is if I connect one or more Ip Phone model 7960G tey're not powered by the cat 3750 PoE, but if I connect another type of ip phone (7912,7961,7960) they're a rightly powered by the PoE of the catalyst 3750 V2.

If I connect the 7960G to an old 3750 (non V2) it works perfectly.

The Cat 3750 V2 are running with an IOS ver 12.2.(50)SE and I'm going to update to 12.2.(53)SE to try to fix this issue.

Does anyone have an idea about how I can fix this issue?


Fabio Coppotelli

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Leo Laohoo Sun, 01/17/2010 - 13:55
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Different phone models use different power.  I believe the 7910 is 5.0w, the 7940/7960 use 6.3w.  If some phones do not work on the 48-port PoE, then check the remain power allowance using the command "sh power inline".

krishnakumarr Sun, 01/17/2010 - 20:40
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I believed the 7940/7960 this model is class 3 phones this will use more power 14- to 17 voltage can you  verify the switch will deliver this much voltage to phones

iusse show inline power command

first you put the phone auto mode and check the voltage how much voltage draw form the switch


you can set the voltage manually

power inline static max 14000


krishna kumar

fcoppotelli Tue, 01/19/2010 - 02:00
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Hi everybody,

after the IOS upgrade to the version 12.2(53)SE the ip phones are now rightly powered by the Catalyst.

Thanks to everybody.


BSILA OMAR Tue, 03/02/2010 - 04:20
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Cisco Bug ToolKit

CSCta78591 Bug Details

3560v2/3750v2  POE switches not providing power to Cisco legacy IP Phones


Catalyst 3560v2/3750v2 POE switches do not  provide power to some Cisco legacy IP phones.


This  issue is seen with Catalyst 3560v2/3750v2 switches and the following  Cisco legacy IP phone models and revisions:

- Cisco CP-7940G IP  phones with hardware revisions:

68-1735-09 Rev. C0

- Cisco  CP-7960G IP phones with hardware revisions:

68-1679-07 Rev.  E0 
68-1679-08 Rev. A0


None at  this time. This problem is under investigation.


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