How do you make a cisco switch a POE device?

nice343

any help will be appreciated

Fugazi1000

If by POE you mean Power over Ethernet (PoE) then the switch needs to be specifically designed to provide power (Power Sourcing Device/PSE) or an external power supply local to the device that needs power can be used.

You could also use a 'midspan' device to inject power such as: http://www.networkwebcams.com/product_info.php?products_id=395

(I do not endorse the product or company and it's purely an example)

nice343

we have a 3750 which is a POE switch don't we have to upgrade the power to make it possible?

Netstudent

If the switch is PoE capable, then it should be plug and play. Some phones or devices might require a little bit of power tweaking within the switch.

Plantwiz

nice343 wrote:

we have a 3750 which is a POE switch don't we have to upgrade the power to make it possible?

Cannot imagine why you would upgrade the power? Never run into this. Typically devices designed for/with PoE send a small amount of voltage down the line to power the device. Nothing else necessary. (at least with the things I've used)

nice343

the 3750 is POE switch but only about half of the phones are powering up. The rest aren't.

This is **** me off

dtlokee

When you say "upgrade the power" do you mean the amount of power? Many of the desktop type switches can only provide 370w of power, (at 15.4 watts per interface that would only be 24 interfaces) but typically the only units you can upgrade are the modular switches like the 4500 and 6500 which can take multiple 1300 watt (or more) power supplies.

Netstudent

nice343 wrote:

the 3750 is POE switch but only about half of the phones are powering up. The rest aren't.

This is **** me off

Ya I know how you feel. I had some hair pulling instances with cabling myself when we cutover.

We had about 5 or 6 cable runs that would get PoE but no data/DHCP. OR the machine would get network connectivity but when you plugged the phone into the same data run, it got no PoE.

Needless to say we ended up re-running those suckers. Bad pairs. I tried to make a case for a cable audit before the cutover but it was deemed too expensive. Well because of that we had to work extra late to get the cutover complete before the deadline. We had so much extra stuff on our plate during the middle of the cut over because these things weren't done before hand.

malcybood

nice343 wrote:

the 3750 is POE switch but only about half of the phones are powering up. The rest aren't.

This is **** me off

Although it is a POE switch, you still have to make sure POE is activated on the switch ports. Have you verified that POE is configured on all fastethernet switch ports? It may be that the phones that are not coming on are patched into ports that are not activated for POE.

Example on how to configure fa1/0/1 below

Switch# configure terminal
Switch(config)# interface fastethernet1/0/1
Switch(config-if)# power inline auto
Switch(config-if)# end

Switch# show power inline fastethernet1/0/1
Interface Admin Oper Power Device Class
(Watts)

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Fa1/0/1 auto on 6.3 Cisco IP Phone 7960 Class 2

You should be able to configure a range of ports in the same way......I think the command on a 3750 is as below but someone correct me if I'm wrong

switch(config)#interface range fastethernet1/0/1 - 48
switch(config-if)#power inline auto
Switch(config-if)#end

Verify by below
Switch#show power inline ?
Switch#show controllers power inline

Another thing to confirm and let us know is, if you plug a PC/laptop into one of the ports that doesn't give POE does the PC get a DHCP IP address? If so this would most likely point to being linked to the above.

Hopefully this helps

malcybood

Just another couple of thoughts on this........

Are you using a standard type of IP handset? Wht model? Are there any known bugs/issues with switch model or IOS version compatibility?...The reason I ask is we use Nortel VOIP in a POE switch infrastructure with Nortel i2002 and 2004 handsets. There are 2 "phases" of the handsets phase 1 and phase 2 of the handsets......but hey this is Nortel we're talking about

With certain switch models the phase 1 handsets require either an external power block or an in line power dongle to "boost" the signal if you like. The phase 2 handsets are compatible with all switch versions (Nortel 460 and 470pwr) and don't require in line power dongle due to the way they're wired.

Another couple of thoughts;

- Is there any MAC address port security on any of the ports?
- Have you checked the interfaces are not shutdown by applying no shut to all of the ports? (if you get a data connection ip address as suggested before kinda answers this one in itself but worth checking)