Field Notice: FN74267 - Cisco NCS-55A2 and NCS-57C3 Routers May Experience MPA Ejector Open, Leading to an MPA Shutdown - Software Upgrade Recommended

The ejectors on Cisco Network Convergence System (NCS) NCS-55A2 and NCS-57C3 Routers (chassis) required for MPA (modular port adapter) operation are susceptible to contamination, which can cause random and unintended removal events, resulting in an MPA shutdown and impacting traffic.

This issue was discovered during an analysis of field returned units. It was observed that the MPA ejectors were non-operational due to contamination. 

The following ejector alarm will be observed on Cisco NCS-55A2 and NCS-57C3 on a running system, even if the user has not attempted to remove the MPA:

LC/0/0/CPU0:2024 Dec  5 07:41:22.230 UTC: mpa_mgr[247]: %PLATFORM-MPA_MGR-3-MPA_EJECTOR_OPEN_POWERDOWN : Ejector being open for physical removal, shutting down MPA 0/0/1

If you observe the ejector alarm, you do not need to do a Return Materials Authorization (RMA) for the device. To avoid a power down of an MPA due to ejector alarm, Cisco recommends upgrading to Cisco IOS XR Release 24.2.21.

After upgrading the software, you may disable the ejector switch function, which will not hinder the performance of the MPA.

To disable the ejector switch for the MPAs, use the following commands:

RP/0/RP0/CPU0:ios#conf t
Wed Apr  2 12:49:45.726 UTC 
RP/0/RP0/CPU0:ios(config)#hw-module subslot all ejector-disable
RP/0/RP0/CPU0:ios(config)#commit

Note: If the ejector function is disabled using the preceding commands, make sure to use the Managed OIR procedure when removing the MPA.

To do a managed online insertion and removal (OIR) of MPAs, use the following steps:

1. Shut down the MPA using the hw-module subslot rack/slot/subslot shutdown command.
2. Confirm that the LEDs have gone from green to off.
3. Use the do show platform command to verify that the MPA to be removed is in the disabled state.
4. Physically remove the MPA to be replaced.
5. Physically insert the replacement MPA. After inserting the MPA in the slot, tighten the MPA screw located on the right side within 10 seconds. Ensure that you first tighten the right screw and then the left.
   • Note: Tighten the captive screws on the MPA within 10 seconds. Otherwise, the MPA will shut down and move to Disabled state. To recover the MPA, tighten both the captive screws and then execute the hw-module subslot rack/slot/subslot reload command.
6. Return the MPA to the up state with the no hw-module subslot rack/slot/subslot shutdown command.

The Hardware Installation Guide for Cisco NCS 5500 Series Modular Routers has been updated. See the Managed OIR section under Handling Modular Port Adapters for the most up-to-date instructions.