Field Notice: FN – 72541 – Some NCS 540 Routers Might Experience Multiple Reloads or Show No Console – Software Upgrade Recommended

Problem Description

Some Network Convergence System (NCS) 540 Series routers might encounter no console or be subjected to multiple reloads with Cisco IOS® XR Release 7.0.x, Release 7.1.x, Release 7.2.x, Release 7.3.x , and Release 7.4.x. Routers in this state will also display blinking green LED lights on the front panel.


The root cause of the issue is an updated firmware requirement for the CPU. Routers currently shipped from manufacturing have the fix incorporated.

Problem Symptom

These symptoms might be exhibited with Cisco IOS XR Release 7.0.x, Release 7.1.x, Release 7.2.x, Release 7.3.x, and Release 7.4.x.

  • A router with no reboot history might experience multiple reloads. – CSCvz15167
  • A router might be subjected to an unexpected reload abruptly with a Kernel dump crash. – CSCwd50606
  • The PWR and FAN LEDs, on the front panel of the unit, are blinking green. – CSCvz19041
  • The router might also reboot continuously with a Sequenced Packet Protocol (SPP) initialization failure message. – CSCvz19041


Routers with the issues must be upgraded to Cisco IOS XR Release 7.3.2 or later, where the fixes are incorporated.

The table listed provides the Software Maintenance Upgrades (SMUs) and base releases where the fixes are enabled for corresponding Defect IDs.

This advisory is available at the following link:

Leave a Reply

Your email address will not be published. Required fields are marked *