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[ACX/MX] After l2-circuit asynchro-notification sent to another device, LED of the interface is up even after SFP removed



Article ID: KB36162 KB Last Updated: 22 Aug 2020Version: 1.0

After asynchro-notification is sent to another device, LED of the physical interface that was notified is solid. The state persists even after SFP removal.


Given the following example topology, PE1 and PE2 form L2-circuit to connect CE1 and CE2:

+-------+             +-------+    +-------+    +-------+              +-------+
|       |     ge-1/1/1|       |    |       |    |       |ge-1/1/2      |       |
|  CE1  +-------------+  PE1  +----+   P   +----+  PE2  +--------------+  CE2  |
|       |(1)          |       |    |       |    |       |(3)           |       |
+-------+             +-------+    +-------+    +-------+              +-------+


Symptoms along the timeline:

  1. Link down event happens at CE1 facing PE1 as L2-circuit interface.
  2. PE1 transfers asynchronous-notification message towards PE2.
  3. At PE2, ccc state goes down. However, the physical optics remains up. LED keeps lighting even after removing the SFP.

This is expected behavior. It is designed this way to notify the user about an abnormal link down. This is for RPD to keep the l2circuit information. Having RPD keep l2circuit information, we had a limitation where the interface had to be kept up regardless of whether SFP is plugged on or off.


This is an expected behavior and has no service impact.  Upon receiving of the asynchronous-notification, keeping the physical interface up is by design. This is for RPD to keep the l2circuit information. (In your test, RPD running on PE2.) Having  RPD keep l2circuit information.

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