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| Affected Product Name | Description | Comments |
|---|---|---|
| DS-C9124V-K9 | MDS 9124V 64G Fabric Switch Base PID | |
| DS-C9132T-K9 | MDS 9132T 32G 1 RU FC switch, w/ 8 active FC ports, No Fans | |
| DS-C9148S-K9 | ^MDS 9148S 16G FC 48-port switch (w/ 12 ports active) | |
| DS-C9148T-K9 | MDS 9148T 48P 32G Fibre Channel switch w/ 24 Ports activated | |
| DS-C9148V-K9 | MDS 9148V 64G Fixed Fibre Channel Switch | |
| DS-C9220I-K9 | MDS 9220I 1RU Multiservice switch, BASE PID | |
| DS-C9250I-K9 | ^MDS 9250i 50 port switch base config(20xFC, 8xFCoE, 2xFCIP) | |
| DS-C9396S-K9 | MDS 9396S HW base (48 ports active) | |
| DS-C9396T-K9 | MDS 9396T 96P 32G Fibre Channel switch w/ 48 activated ports | |
| DS-C9396V-K9 | MDS 9396V 64G Fixed Fibre Channel Switch Base |
| Defect ID | Headline |
| CSCws09730 | Fabric Switches reboot after the mgmt0 interface link goes down. |
Cisco MDS 9000 Series Fabric Switches that are running Cisco NX-OS Software Release 9.4(4) may experience an unexpected system reload when the management interface (mgmt0) experiences an ungraceful link failure or flapping condition. This issue affects specific models in the Cisco MDS 9000 Series product line and can result in service disruption.
A software defect, CSCws09730, was introduced in Cisco NX-OS Software Release 9.4(4) that causes the port service to crash when the management interface (mgmt0) link state ungracefully changes to down. This defect can lead to repeated service crashes and ultimately trigger a disruptive automatic system reload based on the High Availability (HA) policy.
When this issue occurs, one or more of the following symptoms may be observed:
1. Unexpected Switch Reload - The switch experiences an unplanned reload, causing service disruption.
If the condition leads to a reload, the system logs will show repeated crashes of the port service:
%SYSMGR-2-SERVICE_CRASHED: Service "port" (PID 3920) hasn't caught signal 11 (core will be saved).
%SYSMGR-2-SERVICE_CRASHED: Service "port" (PID 32356) hasn't caught signal 11 (core will be saved).
%SYSMGR-2-SERVICE_CRASHED: Service "port" (PID 32403) hasn't caught signal 11 (core will be saved).
%SYSMGR-2-SERVICE_CRASHED: Service "port" (PID 32472) hasn't caught signal 11 (core will be saved).
After the reload, the show system reset-reason command will indicate that the reset was triggered by the HA policy for the port service:
----- reset reason for module 1 (from Supervisor in slot 1) ---
1) At 217995 usecs after Wed Nov 12 18:22:48 2025
Reason: Reset triggered due to HA policy of Reset
Service: port hap reset
Version: 9.4(4)
2. Garbled Syslog Messages - Console or syslog output displays corrupted characters when the mgmt0 interface goes down:
%PORT-5-IF_DOWN: Interface mgmt0 is down () \201^U^[
This issue is triggered when the management interface (mgmt0) link goes down ungracefully or flaps, typically due to one or more of the following:
Bringing the link down gracefully using a configuration shutdown of the mgmt0 interface from the MDS side does not trigger the issue.
Cisco has identified the following workarounds and solutions for this issue:
Upgrade to a fixed software release: This issue will be fixed in the upcoming Cisco NX-OS Software Release 9.4(5) (available in Q1 2026) and later releases.
If immediate upgrade is not possible, downgrade to Cisco NX-OS Software Release 9.4(3b), which does not contain this defect.
To minimize the risk of triggering this condition while running affected NX-OS code, do the following:
To identify the product ID (PID) of a device, use the following command:
switch# show inventory | head lines 2
NAME: "Chassis", DESCR: "MDS 9148V 48X64G FC (1 RU) Chassis"
PID: DS-C9148V-K9 , VID: V01 , SN: JPG2631008X
To check which Cisco NX-OS Software release is running on a device, use the show version command:
switch# show version
...
system: version 9.4(4)
...
If Cisco NX-OS Software Release 9.4(4) is running on any of the affected product models listed above, the switch is considered vulnerable.
| Version | Description | Section | Date |
| 1.0 | Initial Release | — | 2026-JAN-20 |
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