Field Notice: FN74294 - New Memory Component Introduction in Cisco Network Convergence System 540 Routers May Cause Multiple Reloads with Cisco IOS XR Software Releases Earlier Than 7.9.1 - Software Upgrade Recommended

Available Languages

Updated:January 30, 2026
Document ID:FN74294

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:
2026-Jan-30
Last Published:
2026-Jan-30
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
N540-24Z8Q2C-M NCS 540 Series 24x1/10GE, 8x10/25GE, 2x100GE Fixed Chassis  
N540-24Z8Q2C-SYS N540-24Z8Q2C Base HW Flex. Consumption Need Smart Licensing  
N540-ACC-M NCS 540 Series 24x1/10GE, 8x10/25GE, 2x100GE Fixed Chassis  
N540-ACC-SYS NCS540 24x1/10G SFP+, 8x1/10/25G SFP+/SFP28, 2x100G QSFP28  
N540-ACC-SYS-V NCS540 24x1/10G SFP+, 8x1/10/25G SFP+/SFP28, 2x100G QSFP28  
N540X-ACC-SYS NCS540 CC 24x1/10G,8x1/10/25G SFP+/SFP28, 2x100G QSFP28  




Defect Information


Defect IDHeadline
CSCwc35622NCS540 : Micron 4GB DDR came to EOL. New DDR4 8GB support need to be added

Problem Description


A new DDR4 8 Gb memory component is being introduced in Cisco Network Convergence System (NCS) 540 Routers. This new memory component is not compatible with Cisco IOS XR Software releases earlier than Release 7.9.1. Upgrading routers that are equipped with this memory component to software releases earlier than Release 7.9.1 may affect product performance.


Background


The existing memory component in Cisco NCS 540 Routers has reached end of life. To address this, a new hardware version will be introduced for the products that are listed in the Products Affected section of this field notice.


Problem Symptom


Installing a Cisco IOS XR Software release earlier than Release 7.9.1 might cause continuous reloads due to asic init failure. To prevent this, Cisco recommends using the SMU fix described in the Workaround/Solution section of this field notice.


Workaround/Solution


To determine the router hardware version, follow the instructions in the How to Identify Affected Products section of this field notice.

For backward compatibility, Cisco highly recommends installing the prerequisite SMU by January 31, 2026, on routers that are running a Cisco IOS XR Software release earlier than Release 7.9.1. The new hardware version, 2.0, is planned to ship from manufacturing after January 31, 2026.

Cisco IOS XR Software Release SMU type SMU Download Instructions
7.4.2 Reload
  1. Go to the Cisco Software Download page.
  2. Choose Routers > Service Provider Edge Routers > Network Convergence System 540 Series Routers.
  3. Choose the appropriate PID.
  4. Click IOS XR Software Maintenance Upgrades (SMU).
  5. From the left navigation pane, choose the software release.
  6. Install Reboot/Recommended SMU, Tortin : Micron 4GB DDR came to EOL. New DDR4 8GB support need to be added.
7.5.2 Reload
7.6.2 Reload
7.7.1 Reload
7.7.2 Reload
7.7.21 Reload
7.8.1 Reload

Alternatively, deployed Cisco NCS 540 Routers could be upgraded to Cisco IOS XR Software Release 7.9.1 or later as a base release.

The new hardware version is compatible with Cisco IOS XR Software Release 7.9.1 and later. Cisco does not recommend initiating a Return Material Authorization (RMA) for this issue. Routers can return to normal operation by following the solution outlined in this section of the field notice.


How to Identify Affected Products


The new hardware version can be determined by using the following command. The new hardware revision will be 2.0 or later.

RP/0/RP0/CPU0:R1_new#show diag chassis

Sample output:

sysadmin-vm:0_RP0# show diag chassis
DDD MM DD HH:MM:SS UTC+00:00
Diag Information For : 0 Rack 0-IDPROM Info
Product ID : N540-ACC-SYS
VID : V02
Serial Number : FXXXXXXXXXX
CLEI Code : INM9600ERB
Part Number : 73-101883-XX
Part Revision : B0 H/W Version : 1.1

Top Assembly Block:
Serial Number : FXXXXXXXXXX
Part Number : 68-6965-XX
Part Revision : G0
Mfg Deviation : 0
H/W Version : 2.0
Mfg Bits : 0

Revision History


VersionDescriptionSectionDate
1.0Initial Release—2026-JAN-30

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