The interfaces are blinking of many different colors just like a Christmas tree.

Ports leds behavior looks different across several EX4300-MP switches I have.

About the port leds, please consider these two things:

A) Some ports are capable to run at higher speeds:

B) Leds on the left mean something different than leds in the right:

The led in the left, which is some color between green and yellow, this led represents the Link/Activity (these leds are only of 1 possible color).

The led in the right, which is a more intense green color, represents the Status of the port (these ones could show up in many different colors).

This is what the behavior means for the link/activity LEDs:

Table 11: Link/Activity LED green:

• Blinking—The port and the link are active, and there is link activity.
• On steadily—The port and the link are active, but there is no link activity.
• Off—The port is not active.

Now reading the status leds is where the tricky part is, because their color and meaning will vary depending on which parameter you have selected on the front panel.

For example selecting SPD parameter:

“Indicates the speed. The speed indicators are:

• Unlit—10 Mbps
• Blinking green—100 Mbps
• Steadily green—1000 Mbps
• Blinking amber—5000 Mbps
• Steadily blue—10000 Mbps”

If you toggled to a different parameter (SPD, DX, EN, POE), then the status leds should change accordingly to display different information. To check all possible modes, please refer to the link:

https://www.juniper.net/documentation/us/en/hardware/ex4300/topics/topic-map/ex4300-chassis.html#port-ex4300-network-uplink-module-leds__d82e383