Field Notice: FN74264 - Cisco ASR 9000 Series Modular Systems May Not Work Properly During Replacement or Reimage for Systems Containing Third-Party SMUs - Software Upgrade Recommended

Cisco ASR 9000 Series Modular System line cards and/or Route Processors (RPs) may enter a reboot loop during the re-image operation. This occurs when a third-party SMU is installed on the system. This issue affects all Enhanced XR (eXR) modular platforms that are running Cisco IOS XR Software Release 7.6.1 and later and have third-party SMUs installed, resulting in increased Return Material Authorizations (RMAs) being observed in the field.

The reboot loop was encountered when the RP or line card tried to synchronize with Cisco IOS XR Software on the active RP. This only impacts systems that have a third-party SMU installed.

Note: The card, whether it is an RP, line card, or fabric card (FC), is not exposed to this issue if it boots Cisco IOS XR Software from the local disk, which occurs when the local installation is identical to the one on the active RP.

If either of the following conditions is observed in your Cisco ASR 9000 Series routers, proceed to the Workaround/Solution section of this field notice.

Condition 1: A third-party SMU has been installed on your system.

To identify a third-party SMU, see the package name. SMUs with a package name that do not begin with the platform name are third-party SMUs. In the following example, third-party SMUs are highlighted in bold: 

sysadmin-vm:0_RP0# show install active summary
Thu Feb 13 15:36:33.594 UTC+01:00
Active Packages: 4
asr9k-sysadmin-7.10.2 version=7.10.2 [Boot image]
asr9k-sysadmin-shared-7.10.2.2-r7102.CSCwk16782
ramfs-ima-1.0.p1-r0.0.r7102.CSCwj22270.admin
ramfs-ima-1.0.p1-r0.0.r7102.CSCwj22270.host

Condition 2: If a system is impacted by this issue, output is reported during the replacement and re-image process, as shown in the following example:

RP/0/RP0/CPU0:ios#sh platform
Node              Type                       State             Config state
--------------------------------------------------------------------------------
0/RP0/CPU0        A99-RP3-SE(Active)         IOS XR RUN        NSHUT
0/RP1             A99-RP3-SE                 SW_INACTIVE       NSHUT
0/FT0             ASR-9922-FAN-V3            OPERATIONAL       NSHUT
0/FT1             ASR-9922-FAN-V3            OPERATIONAL       NSHUT
0/FT2             ASR-9922-FAN-V3            OPERATIONAL       NSHUT
0/FT3             ASR-9922-FAN-V3            OPERATIONAL       NSHUT

--snip--

Solution:

Cisco IOS XR Software releases 24.2.21, 24.4.2, 25.1.1, and later are considered to be fixed releases that do not require the installation of an SMU.

For releases earlier than Cisco IOS XR Software Release 24.2.21, Cisco recommends proactively installing SMUs. First, ensure that no third-party SMUs are installed on the device, and then deploy the appropriate SMU according to the following instructions:

Step 1: Download the appropriate SMU as shown in the following table. 

1. Go to the Cisco Software Download page.
2. Choose the appropriate product from the list.
3. Click the IOS XR Software Maintenance Upgrade (SMU) link.
4. Choose the appropriate release for which you want to install the SMU.

Step 2: If the affected line card is stuck in a boot loop or is in the SW_INACTIVE state, shut down the line card using the sysadmin configuration hw-module shutdown location command. If an RP is affected, the affected RP must be physically removed from the chassis. This ensures proper handling before further troubleshooting or recovery steps are taken.

Step 3: First, remove any third-party SMUs that are running on this device. Then, upgrade from an affected release of Cisco IOS XR Software to a fixed release as shown in the following table:

Important: The Software package selected at this stage must not contain any third-party SMUs.

To upgrade from an Affected Cisco IOS XR Software Release to a Fixed Release:

Step 4: Install the desired third-party SMU as shown in the following table. This step can be combined with a Cisco IOS XR Software upgrade:

Recommended Action: If no third-party SMUs are in use, the preferred solution is to combine Step 3b and Step 4a because this sequence would require the system to reload only once, minimizing downtime and operational impact.

The proposed SMU should not be installed on a device that is already running a third-party SMU.

The proposed SMU, or Cisco IOS XR Software release that integrates the fix, should not be installed together with any third-party SMU when the install operation is started form a software package that does not contain the fix.

A third-party SMU can be safely installed on a device only when the install operation starts while already having the fix.