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Ethernet Switches & Routers

Video: Configuring Power Over Ethernet (PoE)

by DennisMSmith on ‎06-20-2016 07:44 AM - edited on ‎03-20-2017 09:38 AM by Community Manager (1,446 Views)

In this video, we'll show you how to configure Power Over Ethernet (PoE) on Brocade campus switches.



Video Transcript:


0:00 - This is the Brocade campus feature explainer series I'm Terry Henry and

0:04 - in this episode we're going to cover how to configure power over Ethernet in

0:08 - particular on the ICX series this time.

0:12 - So by default POE is disabled on all of our ports so we need to go in and

0:18 - and enable that so if we go into config t and we'll do a range of ports

0:23 - 1/1/1 to 1/1/8 in this example.

0:28 - So to just turn on POE with its default parameters we just type inline power

0:33 - and that's all there is to it so in line power is now on and we can see here it's

0:39 - giving me a message on the console to say that power is enabled on port 1/1/8

0:42 - so indeed I have a POA device plugged into port 1 / 1 / 8 happens to

0:48 - be an IP camera in this case but it could be a phone it could be an access

0:51 - point it could be a terminal could be multiple power drawing devices so to get

0:57 - more detail on that I can do a show inline power and so

1:03 - show inline power here is showing me that there's a total pool for the device

1:07 - in this case it's 370 watts or 370,000 milliwatts if I had redundant power or

1:14 - it was a different device that number would be different but currently I have

1:18 - 370 watts available

1:20 - this is a 24 port switch by the way and so we currently have 350 4.6 watts free

1:28 - and then if we look at the ports we can see each port we can see the admin state

1:33 - so that's where I’ve turned on in line power on those ports are not so I turned

1:37 - it on for 1/2/8

1:38 - it's still offer 9 to 24 the operational state so we see that it's on on 1/1/8

1:44 - so we know there's a POE device plugged in here that POE device is

1:48 - currently consuming 2.9 watts but its allocated 15.4 so the device itself the

1:56 - pd told us that it was in 802.3af device and that it was a class 3 device so it

2:02 - needed 15.4 watts allocated is it really going to use 15.4 watts I don't know but

2:09 – be forewarned that just because this consume number is less than the allocated

2:14 - doesn't mean that that device is not capable of pulling more so for example

2:17 - if it's a phone and you have it on speakerphone it will pull more

2:23 - power than if it's on the handset or in this case if its own IP camera

2:30 - if the IR bulbs are lit then it's going to pull more power in a you in a dark

2:36 - scenario than it is in a full sunlight scenario so it will change the amount of

2:40 - power that it's consuming so it's going to allocate the most that can possibly

2:44 - use its told us it's a class three device or class 3 is 15.4 watts so

2:50 – 4 watts 7 watts 15.4 watts 30 watts 95 watts for the different power classes

2:56 - priority will talk about in a bit

2:59 - and there's if there was an error so it was trying to pull more power than was

3:03 - allocated either by class or by a power then you will show a fault here or if

3:08 - there was a short in the wire for example that it's going to show a fault

3:11 - here

3:11 - so if we wanted to be more granular and how much power we allocate to the port's

3:19 - rather than using the default or the or the pd class we can set a class on the

3:24 - port so we could do a inline power by class and say class 2

3:34 - so we know the class 2 is 7 watts

3:37 - so if we look back at the show inline power here I can now see

3:43 - so there's no so this device is now pulling for 4.2 watts actually so we can

3:50 - see that is now pulling 4.2 watts and I've allocated 7 so even though the

3:56 - device is telling me it's a class three PD device

3:59 - I've allocated class 2 to this or 7 watts so the most it's going to be

4:04 - allowed on this port is 7 watts of a device tries to pull more than that so

4:08 - if you pull the plug in a you know dual radio access point is trying to pull

4:12 - 15.4 watts that device is going to go to into an overload state but in this case

4:17 - I'm not pulling more than the 7 so that so that

4:20 - it's fine I can also do instead of power by class

4:27 - I could do it power limit and I can set the limit

4:38 - excuse me I can set the limit in anywhere from 1 watt to 30 watts or on

4:49 - a 7450 it could be 95 watts so anywhere in that range any and we set that in milliwatts

4:54 - so I could say six thousand for example so that means if I go back and do the

5:02 - show inline power and prior we were doing it by class we were

5:08 - we're doing in class to which was 7 watts or 7,000 milliwatts now we're

5:13 - allocating six thousand watts here right so it's consuming 4.2 out of out of

5:18 - six if I set that to a number that was too low for example to set that - 4000

5:29 - the device is says that powers disabled in that part because a PD overload so

5:33 - the device plugged in was trying to pull more than I had allocated to that

5:37 - and so it's not going to let that port come up

5:41 - so let me set that back to a reasonable number

5:48 - and then power should come up and be restored on that port so the other thing

5:55 - you can do is priority so by default

5:58 - again if we do a show inline power we can see that everything has a priority

6:03 - of three

6:04 - by default which is the lowest possible priority so they go 3 2 1 so 1 is the

6:10 - highest priority and what priority does is if the switch runs out of power in

6:14 - that pool so for example if you are running a device with dual power

6:18 - supplies and you had allocated more power than one power supply could handle

6:23 - what happens if that second power supply fails and you don't have enough power to

6:27 - power all the devices

6:28 - so what happens is the priority to higher the priority

6:32 - the more that the higher priority is for that port to stay on so if it's a if the

6:39 - priority one device those have to stay on so maybe those our phones and priority two

6:43 - devices might be access points and you know so you can allocate the priority or

6:49 - if you've got a call center that has to stay up those would be the priority one

6:53 - versus the desk phones which are priority two

6:55 - etc but by default everything is going to be priority three so everything is

6:59 - the same priority so all we gotta do is set it to something better than that

7:03 - so if I wanted to go to you know to a particular port 1 / 1 / 8 and then we

7:11 - could do a inline power and give it a priority of two for example and then

7:23 - look back at the inline power

7:25 - I have a priority of two on this port which means that it in the event of an

7:29 - emergency and I run out of power that port is going to stay on before all of

7:36 - the the priority threes so so that is a good way to prioritize your most

7:43 - important devices

7:44 - so that's it for this episode

7:48 - thanks for joining