Field Notice: FN - 63697 - Protective Boot on Certain Network Cables Might Push the Mode Button and Cause an Unexpected Reset on the 48-Port Models of Cisco Catalyst 3650 and 3850 Series Switches - Workaround Provided

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.

Revision History

Revision	Publish Date	Comments
1.0	11-Nov-13	Initial Release
10.0	12-Oct-17	Migration to new field notice system
10.1	17-Jul-20	Fixed Broken Image Links
10.2	07-Dec-20	Updated the Defect Information and Problem Symptom Sections

Products Affected

Affected Product ID	Comments
WS-C3650-48FD-E
WS-C3650-48FD-L
WS-C3650-48FD-S
WS-C3650-48FQ-E
WS-C3650-48FQ-L
WS-C3650-48FQ-S
WS-C3650-48FS-E
WS-C3650-48FS-L
WS-C3650-48FS-S
WS-C3650-48FWD-S
WS-C3650-48FWQ-S
WS-C3650-48FWS-S
WS-C3650-48PD-E
WS-C3650-48PD-L
WS-C3650-48PD-S
WS-C3650-48PQ-E
WS-C3650-48PQ-L
WS-C3650-48PQ-S
WS-C3650-48PS-E
WS-C3650-48PS-L
WS-C3650-48PS-S
WS-C3650-48TD-E
WS-C3650-48TD-L
WS-C3650-48TD-S
WS-C3650-48TQ-E
WS-C3650-48TQ-L
WS-C3650-48TQ-S
WS-C3650-48TS-E
WS-C3650-48TS-L
WS-C3650-48TS-S
WS-C3850-48F-E
WS-C3850-48F-L
WS-C3850-48F-S
WS-C3850-48P-E
WS-C3850-48P-L
WS-C3850-48P-S
WS-C3850-48PW-S
WS-C3850-48T-E
WS-C3850-48T-L
WS-C3850-48T-S
WS-C3850-48U-E
WS-C3850-48U-L
WS-C3850-48U-S

Defect Information

Defect ID	Headline
CSCuj17317	XE: Certain snagless cables may press on the mode button causing reload

Problem Description

Certain types of snagless Ethernet cables have protective boots that extend too far forward and above the plastic latching tab.

When this type of cable is installed in Port 1 of any 48-port model of the Cisco Catalyst C3650 or C3850 Series switches, the boot might press and hold the Mode button, which invokes Express Setup and reboots the system. (Reference Figures 1 through 3 for illustrations of the issue.)

Note: This type of boot-cable can partially obscure port LEDs, air vents, and USB ports.

Figure 1. Problematic Cable before Complete Insertion

Figure 2. Problematic Cable Completely Inserted

Figure 3. Problematic Cable Completely Inserted (side view)

Background

Snagless Ethernet cables were developed many years ago in order to protect the plastic latching tab from becoming snagged, bent, or broken. There are various ways to achieve this goal, but the most common is to hide the tab under a plastic shroud or boot.

Numerous types of snagless cables are available. However, most are designed in such a way that the protective device is less prominent and/or held more tightly to the tab, which prevents the aforementioned drawbacks.

Problem Symptom

When Express Setup is inadvertently invoked by the protective boot of the cable, these messages are seen in the syslog:

%SYS-7-NV_BLOCK_INIT: Initialized the geometry of nvram
%EXPRESS_SETUP-6-CONFIG_IS_RESET: The configuration is reset and the system will now reboot
%SYS-5-RELOAD: Reload requested by NGWC led process. Reload Reason: Reload command.
%STACKMGR-1-RELOAD_REQUEST: 1 stack-mgr: Received reload request for all switches, reason Reload command
%STACKMGR-1-RELOAD: 1 stack-mgr: Reloading due to reason Reload command.

After this occurs, the device resets. The startup configuration is erased once the device enters Express Setup.

Note: The Catalyst 3650 and 3850 Series switches that run on Cisco IOS XE Releases 16.x and 17.x are not impacted by this issue.

Workaround/Solution

There are three options used in order to address this problem:

• Use a snagless cable with a less-pronounced boot in Port 1.
• Trim the boot on the cable that is installed in Port 1.
• Disable Express Setup with this command while in config mode:

  3850(config)# no setup express

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

• Open a service request on Cisco.com
• By email
• By telephone

Receive Email Notification For New Field Notices

Cisco Notification Service—Set up a profile to receive email updates about reliability, safety, network security, and end-of-sale issues for the Cisco products you specify.