I recently deployed a number of MR42's connected to WS-C3850-48P running 3.07.05e and noticed they all came up in low power mode.
Interface Admin Oper Power Device Class Max (Watts) --------- ------ ---------- ------- ------------------- ----- ---- Gi1/0/44 auto on 15.4 MR42 4 30.0 Gi1/0/45 auto on 15.4 MR42 4 30.0 Gi1/0/46 auto on 15.4 MR42 4 30.0 Gi1/0/47 auto on 15.4 MR42 4 30.0
I checked through doc 2068 on configuring Cisco switches but I already had LLDP running and didn't want to statically set power on the ports.
I found the following command fixed the issue when entered on each interface connected to an AP:
power inline port 2-event
The APs immediately switched to full 802.3at (no reboot required):
Interface Admin Oper Power Device Class Max (Watts) --------- ------ ---------- ------- ------------------- ----- ---- Gi1/0/44 auto on 30.0 MR42 4 30.0 Gi1/0/45 auto on 30.0 MR42 4 30.0 Gi1/0/46 auto on 30.0 MR42 4 30.0 Gi1/0/47 auto on 30.0 MR42 4 30.0
Just thought I'd share this in case anyone else comes across the same issue.
If you go:
Wireless/Access Points/[click on an access point]
Down the bottom it will say how much power it is actually using.
I just checked one of mine, and it has negotiated 802.3at (30W) but is only using 5W to 6W at the moment. It is possible the 3850 was only giving 15W because the access point had not yet asked for more power.
Possibly yes but all of the APs on this site were showing as low power mode:
and as soon as I entered that command they all showed as 802.3at:
Interestingly we have other sites with 3850's that we haven't entered this command on. Only differences I can see are this:
Model Number Hardware Version Software Version Needed 2-event? WS-C3850-48P V04 3.03.05SE NO WS-C3850-48P V07 3.07.05E YES
So next step would be to upgrade the V04 site to 3.07.05e to see if that changes anything but I haven't got spare time at the moment. Anyway, whatever the cause, just wanted to share to save people time if it happens to them.
PoE 802.3af means running in low power mode or PoE 802.3at?
I am using MR53 device. See my screenshot below... Mine doesn't say running low power mode.
PoE 802.3af means PoE standard which goes up to 15 watts. PoE 802.3af is PoE+ which goes up to 30 watts. Devices that can use that much but knows it limited to 15 watts will say "low power mode". UPoE by Cisco goes up to 60 watts but not yet a defined standard.
Hey @Dave_Lewis, check this out as well. Could just be the default config is stuck because of how the devices initially communicated with each other.
Hope this helps!