Cisco SG-250-10P / No POE available

[testag]

Hi,

I have attached 3 Ubiquiti Nano Switches to that Cisco SG-250-10P. Non of them is getting power from Cisco. By default POE is enabled I guess resp. I cannot find and esplicit setting in Switch GUI. Any idea why the Nano Switches don't get power?

Regards, testag

[Mark Malone]

Hi
Check do they have supporting POE types , dop the nanos use 802.3af or at POE ?
I know some models of 250s only support AF 15watt not 60watt AT

[testag]

As far as I know the nano switches use POE. In the specs 802.3af is not mentioned. The SG-250 can do 60W per port.

Any other idea what the problem might be?

[Mark Malone]

If POE is not working it can only be 1 or 2 things

The POE type is not supported between the devices , check the actual spec of what the nano is using
The board is not supplying POE correctly and you have a hardware issue , you could test this easily by plugging in another standard POE device like a phone

Its on by default , requires no config so its a miss match or fault usually

Reading the admin guide for the 350 model its a Cisco TLV POE meaning it will supply 60watts to Cisco devices that supports that method or 30watt to standard devices

whats the exact mdoel of these Nano device the part no

[testag]

It is this model https://www.ui.com/accessories/nanoswitch/ .

As I noticed Cisco is suplying 48V and Nano 24V. I thought POE is strandardized?

[testag]

Do you mean when I use a different switch and replace the Cisco one it will work?

[Mark Malone]

There are multiple versions of POE 802.3AF and AT
these look to be using AT as they need 30watts looking at the doc

do you have any other POE devices you can just test the POE is actually working like a phone ?
Is there anything in the logs

This doc states you support both types of POE anyway
https://www.cisco.com/c/en/us/products/collateral/switches/250-series-smart-switches/datasheet-c78-737061.html

802.3at PoE+ and 802.3af PoE delivered over any of the RJ-45 ports within the listed power budgets


The following switches support 802.3at PoE+, 802.3af, and Cisco prestandard (legacy) PoE. Maximum power of 30.0W to any 10/100 or Gigabit Ethernet port, until the PoE budget for the switch is reached. The total power available for PoE per switch is as follows:

Model


Power dedicated to PoE


Number of ports that support PoE

SF250-24P


185W


24

SF250-48HP


195W


48

SG250-08HP


45W


8

SG250-10P


62W


8

[testag]

So, just tested a Cisco VoIP POE Phone on those Ubiquity Swiches. Does not get power. Really bad. Directly connected to Cisco Switch no problem. So does that mean, I can throw away Cisco Switch. I thought this POE stuff was supposed to be compatible