Power over Ethernet (POE) stops working and voltage injection occurs. 'Status 36' messages are observed.

Platforms that apply: EX2300/​EX3400/EX4300/EX4400.

Power over Ethernet (POE) stops working for all affected ports, and in some cases the POE controller fails permanently. The device raises an alarm for voltage injection and status 36 messages are observed.

To check:

When an EX2300/3400/4300/4400 series switch is connected to any device (switch, firewall etc) with POE capabilities and if POE is not turned off on the connected ports, then both of the devices start providing power to each other by inducing a voltage into each other. This is referred to as voltage injection. Once this happens, status 36 error messages are logged into the device.

chassisd[3389]: %DAEMON-3: PoE port name ge-0/0/0 status 36
chassisd[3389]: %DAEMON-3: PoE port name ge-0/0/1 status 36
chassisd[3389]: %DAEMON-3: PoE port name ge-0/0/2 status 36
chassisd[3389]: %DAEMON-3: PoE port name ge-0/0/3 status 36

In some cases, the device will also raise an alarm for voltage injection:

Oct 17 03:11:10  sw1 alarmd[3390]: %DAEMON-4: Alarm set: POE color=YELLOW, class=CHASSIS, reason=PoE voltage injection in Interface ge-0/0/0
Oct 17 03:11:10 sw1 craftd[3402]: %DAEMON-4: Receive FX craftd set alarm message: color: 2 class: 100 object: 148 slot: 0 silent: 0 short_reason=PoE voltage injecti long_reason=PoE voltage injection in Interface ge-0/0/0 id=33554580 reason=16777216
Oct 17 03:11:10  sw1 craftd[3402]: %DAEMON-4:  Minor alarm set, PoE voltage injection in Interface ge-0/0/0

As an electrical effect, voltage injection is time-based. To prevent this issue, disable POE on all ports connected to POE capable devices before the ports are enabled. This is the only way voltage injection can be prevented. Once voltage injection occurs, the only solution is to replace the device.

To disable POE:

set Poe interface ge-0/0/0 disable