Field Notice: FN74028 - New Memory Component Introduction in N540-24Q8L2DD-SYS Routers May Impact Traffic for Releases Earlier than Cisco IOS XR Release 7.10.2 - Software Upgrade Recommended

Available Languages

Updated:May 12, 2025
Document ID:FN74028

Bias-Free Language

The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.

High
Impact Rating:
High
First Published:
2025-May-12
Last Published:
2025-May-12
Revision:
1.0
Cisco Bug IDs:

Notice

THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE FIELD NOTICE OR MATERIALS LINKED FROM THE FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.

Products Affected


Affected Product Name Description Comments
N540-24Q8L2DD-SYS NCS540-2x400G QSFP-DD+8x50G+24x25G  
N540-24Q8L2DD-SYS= NCS540-2x QSFP-DD 400G+8x50+24x25G Spare  




Defect Information


Defect IDHeadline
CSCwb55207Gddr6 16gb Micron support on 6.5.21 SDK

Problem Description


A new GDDR6 16GB memory component is being introduced by Cisco in the Cisco Network Convergence System (NCS) Router N540-24Q8L2DD-SYS. Cisco XR releases 7.10.2 and later are compatible with the component. Product performance may be affected if routers with the new memory components are installed with Cisco IOS XR releases earlier than 7.10.2.


Background


The current memory component in N540-24Q8L2DD-SYS has reached end of life (EOL). A new hardware version will be introduced to support the product


Problem Symptom


Cisco N540-24Q8L2DD-SYS routers that have the new memory component and are installed in systems running a Cisco IOS XR release earlier than Release 7.10.2 may experience performance issues and also exhibit ASIC initialization failure.


Workaround/Solution


The router hardware version can be determined by using the instructions provided in the How to Identify Affected Products section of this field notice.

For backward compatibility, Cisco highly recommends installing the appropriate Software Maintenance Upgrade (SMU) by December 31, 2025 on routers that are operating with software releases listed in the following table. The new hardware version is planned to ship from manufacturing after that date.

Cisco IOS XR Release SMU Link
7.4.2 ncs540l-7.4.2.CSCwb55207.tar
7.5.2 ncs540l-7.5.2.CSCwb55207.tar
7.6.2 ncs540-7.6.2.CSCwb55207.tar
 

Alternatively, deployed N540-24Q8L2DD-SYS routers could be upgraded to a base release of Cisco IOS XR Release 7.10.2 or later.

The installation for SMUs in the preceding table can be validated using the show install active summary | in CSCwb55207 command. In the following example, the output xr-ncs540l-core confirms installation of the SMU:

RP/0/RP0/CPU0:R1_new#show install active summary | in CSCwb55207
 CSCwb55207: xr-ncs540l-core 

The new hardware version is compatible with Cisco IOS XR Release 7.10.2 and later. No action is required for routers already deployed with Cisco IOS XR Release 7.10.2 or later. 

Cisco does not recommend a Return Material Authorization (RMA) for the issue described in this field notice. The routers can resume normal operation with the solution provided in this section of this field notice.


How to Identify Affected Products


The new hardware version can be determined by using the show diag chassis | in Hardware Revision command. The revision of the new hardware will be 7.0 or later. The following is an example of the command and its output:

RP/0/RP0/CPU0:R1_new#show diag chassis | in Hardware Revision
Hardware Revision          : 7.0

Alternatively, the new hardware version can be determined by using the following command. The command output ext_ram_rows=65536 confirms the new hardware version.

RP/0/RP0/CPU0:R1_new#show controllers fia diagshell 0 "config show" location 0/RP0/CPU0 | inc ext_ram_rows
ext_ram_rows=65536

Revision History


VersionDescriptionSectionDate
1.0Initial Release—2025-MAY-12

For More Information

For further assistance or for more information about this field notice, contact the Cisco Technical Assistance Center (TAC) using one of the following methods:

Receive Email Notification About New Field Notices

To receive email updates about Field Notices (reliability and safety issues), Security Advisories (network security issues), and end-of-life announcements for specific Cisco products, set up a profile in My Notifications.

Was this Document Helpful?

FeedbackFeedback

Contact Cisco