SG200-08P always acts as PD although a power supply is connected

[benjaminriggenbach]

Hello

I'm new here.

I have an issue, that a SG200-08P device always obtains power over the ethernet connection.

I have a SG300-10P switch let's say as a main switch.

Then i have situations where i need to connect 2 sg200-08p in daisy chain to one single port of the sg300. The sg200 are always powered by an external power supply. Those do not fail, i've checked that.

The sg300 then provides poe on the connected ports and is not capable to power both sg200, this causes that the sg200 will not boot although they have a power supply connected.

So is there an option i am missing, that i can disable the sg200 as a pd? i don't want them to be powered by ethernet at any time, but i want them to provide poe at some point.

Thank you

[Mark Malone]

Hi

I don't use thee SMB switches but looking at the emulator if you go to the port management - POE - settings .. you can enable disable POE per port of that's what your looking for

https://www.cisco.com/assets/sol/sb/SG200_Emulators/SG200_Emulator_v1-2-9/config/home_SG_200-50P_1_2_9.htm

[benjaminriggenbach]

Hi

Thank you for your answer.

That's correct, you can enable or disable poe per port. But my problem is, that i can't just shut down the poe on port X.

That will work for one situation but chances are big, that in the next situation i will need this port X to provide poe to a pd (e.g. access point) because it is a different scenario without the sg300 switch.

These are touring devices where many situations can happen. That is why all devices are permanently powered by external power supplies and there is no need, that the switches are acting as pd's ever. And the people who are operating the devices are no it guys :-)

[Mark Malone]

Ok maybe im miss understanding this a bit , if you disable the POE it wont try and power anything when a device is connected to the port we know that but...

Are you saying you need the switch to be smart enough to know that a switch is connected and not an AP and only if an AP is connected power that and not the switch so its automated ?

If that's the case no that switch cant do that but a catalyst could as you could do it through an EEM script with reg expression match through a script , I do that for all my phones and pcs so if anyone in Tier 1 non network guys mostly desktop connect a device to the switch it knows what it is , checks the script and then runs it if it matches , if it doesn't it wont do anything and ends the script , that way POE can be enabled depending on what the syslog sees in the regexpression

[benjaminriggenbach]

"Are you saying you need the switch to be smart enough to know that a switch is connected and not an AP and only if an AP is connected power that and not the switch so its automated ?"

Well, kind of.. the one thing i don't understand is why the power source of the sg200 swaps from current to POE from the sg300. When i link 2 sg200 one to another which are both powered on mains, no one receives or sends POE to power the other and that is what i want.

Sorry for my explanation, english isn't my native language.

So maybe the better question is: when i connect 2 POE devices which are both able to act as pd or pse and are both hooked up to mains power, can't they negotiate that neither of each other needs power from the other?