Huawei S6730 Stuck at 40GE After 100GE RTU Activation: Why it happens and how to fix it

Published: July 29, 2026 | Last Technically Reviewed: July 29, 2026

Diagnosis Summary

Activating a Huawei S6730 100GE RTU license does not always change an uplink from 40GE to 100GE immediately.

The RTU establishes the device's right to use the higher port rate. Depending on the exact switch model and VRP software branch, the administrator may still need to:

• confirm that the license file is active;
• allocate a licensed resource to the interface;
• change the port from 40GE to 100GE mode;
• reboot the switch or restart the affected interface;
• install a supported 100GE QSFP28 module, DAC or AOC;
• and configure the peer port for the same 100GE mode.

If the interface is named 100GE but display interface still reports Speed : 40000, the logical conversion may already be complete. The remaining problem is more likely to be the detected cable or transceiver type, cable compatibility, or the far-end port configuration.

The correct troubleshooting order is:

First Check: Which S6730 Is Actually Installed?

Do not begin with the RTU commands until the complete model and software release are known. "Huawei S6730" is a product family, not one hardware platform.

The issue described here mainly applies to models whose high-speed uplinks operate at 40GE by default but can be changed to 100GE using an RTU. Relevant examples include:

• S6730-H24X6C and S6730-H48X6C on applicable VRP V200 releases;
• S6730-S24X6Q and S6730-S48X6Q running V200R024C00 or later;
• S6730-H24X6C-V2 and S6730-H48X6C-V2 on VRP V600;
• S6730-S24X6Q-V2 and S6730-S48X6Q-V2 on VRP V600.

Huawei documents the 100GE RTU capability for the original S6730-S24X6Q beginning with V200R024C00. Its QSFP ports otherwise operate as 40GE interfaces. Huawei also documents the S6730-H24X6C-V2 uplinks as 40GE by default, upgradeable through a 100GE RTU.

Network-Switch.com maintains individual pages for the Huawei S6730-H24X6C and Huawei S6730-H48X6C, as well as the broader Huawei switch portfolio. Use these pages for product and procurement context, but use the matching Huawei release documentation as the authority for commands and license behavior.

Run:

display device
display version
display esn

Record the following before making changes:

Complete SKU:
Product part number:
VRP release:
Patch version:
Affected interface:
Current interface name:
Installed transceiver or cable PID:
Peer model and interface:

The -V2 suffix is especially important because the V200 and V600 RTU workflows are different.

V200 and V600 RTU Workflows

Huawei changed the V200 port-conversion command in V200R020C00. Applicable earlier releases used assign port-speed 100ge; V200R020C00 and later use assign port-type 100ge. This syntax change does not remove the need to verify the minimum release for the specific SKU.

Step 1: Verify That the RTU License Is Active

A license file stored in flash is not necessarily loaded or active.

On relevant V200 releases, begin with:

display license
display license state
display license resource usage

display license state is not available in every VRP build. If the switch rejects it, use display license and display license resource usage, then consult the command reference for the installed version.

If the license has not been activated, Huawei's documented V200 command is:

license active 

Huawei's S1720, S5700, and S6700 Series Switches License Usage Guide, updated October 13, 2025, distinguishes loading the license file from activating it with license active.

Check that:

• the license status is active;
• the license contains the applicable 100GE RTU resource;
• the license is associated with the correct switch;
• the device ESN matches the licensed device;
• and the required resource is not missing or exhausted.

For the relevant V600 models, use:

display license
display license resource usage

A valid license file alone does not prove that the hardware resource has been allocated to the affected interface. Huawei's V600 RTU documentation requires an additional active port-license operation in license view.

Step 2: Check the Current Port Mode and Operational Rate

Run:

display interface brief

Then inspect the affected interface in detail. Use the interface name that currently exists:

display interface 40GE 0/0/1

or:

display interface 100GE 0/0/1

Interface numbering varies by model and platform. A V600 fixed switch may use a format such as 40GE1/0/1. Copy the name from display interface brief rather than assuming the numbering.

Look for the operational speed:

Speed : 40000

or:

Speed : 100000

An interface name beginning with 100GE is not sufficient evidence. The detailed operational speed must also report 100,000 Mbit/s.

Huawei's interface-status guidance, updated March 7, 2026, recommends display interface interface-type interface-number to inspect the current interface state and related details.

Step 3: Apply the Correct Port-Mode Procedure

VRP V200

For supported models running V200R020C00 or later, the documented command is:

system-view
assign port-type 100ge slot 0

Use the slot or device identifier appropriate for the actual switch.

Check the current and pending configuration:

display device port-type configuration

Huawei documents that this command can show the current port type and the port type configured to take effect after restart.

A result equivalent to the following means the conversion has been configured but has not yet taken effect:

Current port type: 40GE
Next-startup port type: 100GE

For the original S6730-S24X6Q and S6730-S48X6Q, do not apply this procedure unless the switch is running V200R024C00 or later, because that is the documented starting release for the 100GE RTU capability.

VRP V600

On applicable S6730-H-V2 and S6730-S-V2 models, the license resource and the interface mode are handled separately.

A representative sequence is:

system-view
license
active port-license 100G interface 40GE1/0/1
quit
port mode 100GE interface 40GE 1/0/1

The active port-license command is entered in license view. Huawei's V600 RTU documentation, dated August 14, 2025, explicitly states that the command should be run in license view after the license has been loaded.

The exact interface number must match the local switch. Before committing the change, use context-sensitive help:

[HUAWEI-license] active port-license ?
[HUAWEI] port mode 100GE interface ?

This prevents commands from another SKU or maintenance release from being copied blindly.

Step 4: Complete the Required Restart

On the applicable V200 workflow, configuring the 100GE port type does not immediately change the running hardware mode.

Save the configuration and reboot:

save
reboot

Huawei's V200 license-control documentation states that the applicable ports work as 100GE ports after the license is activated, the port-type command is executed and the switch is restarted.

On applicable V600 releases, Huawei documents restarting the affected interface as an alternative to restarting the entire device:

interface 100GE1/0/1
restart

The interface name may change during the mode conversion. Follow the warning returned by the actual CLI and the command reference matching the installed release. Huawei's V600 command reference dated March 11, 2026, documents the port mode 100GE operation and the interface restart alternative.

After the restart, verify again:

display license resource usage
display interface brief
display interface 100GE 1/0/1

Step 5: Check the QSFP28 Module, DAC or AOC

If the interface has been converted but still reports 40GE, inspect the inserted medium:

display transceiver interface 100GE 1/0/1 verbose

Use the existing 40GE interface name if the conversion has not yet taken effect.

Record:

• detected transceiver type;
• vendor name;
• vendor part number;
• nominal rate;
• cable or module identifier;
• supported transmission distance;
• temperature and voltage alarms;
• optical transmit and receive power, where applicable.

A QSFP28 physical connector does not by itself prove that the link is running at 100GE. Some ports accept both QSFP+ 40GE media and QSFP28 100GE media. A valid 40GE cable or module may therefore bring the interface UP at 40GE.

For a technical explanation of the form factor and lane architecture, see Everything You Need to Know About QSFP28 Ports.

For DAC and AOC selection differences, see the DAC vs AOC Cable Guide. These internal guides explain the media categories, but the exact Huawei hardware compatibility list remains authoritative for a specific S6730 SKU.

Check:

• whether the medium is 100GE QSFP28 or 40GE QSFP+;
• the complete cable or module PID;
• whether its EEPROM is recognized correctly;
• whether the length is supported by both endpoints;
• whether it is approved for Ethernet use on that switch;
• and whether both ends use the same Ethernet standard.

Network-Switch.com lists 100G QSFP28 DAC cable options, but compatibility must be validated against the exact Huawei SKU, VRP release and peer platform before deployment.

The Useful Community Failure Pattern

A January 2024 r/networking case described two Huawei S6730 switches with licensed 100GE interfaces. The affected interface was UP/UP and named 100GE1/0/2, but the output still showed:

Transceiver: 40GBASE_CR4_QSFP28
Speed : 40000

The author later reported that replacing the cable with a 1 m QSFP28 DAC resolved the issue.

This is a useful symptom match, but it has important limitations:

• the exact S6730 SKU was not provided;
• the original cable PID was not published;
• the peer software details were not included;
• and the result does not establish a universal one-meter limit for all S6730 models.

Huawei's July 6, 2026 S6730-H24X6C-V2 hardware page, for example, lists a 1 m QSFP28 copper cable for a specific supported use and also distinguishes its intended application. Cable support must therefore be checked by exact part number rather than inferred from connector type or length alone.

Step 6: Verify the Peer Port

If the local S6730 configuration and medium are correct, inspect the far-end device.

Confirm that the peer port:

• supports 100GE;
• has any required license activated;
• is configured as one 100GE interface;
• is not fixed at 40GE;
• uses a compatible QSFP28 module or cable;
• and uses compatible physical-layer settings.

Do not describe an FEC mismatch as a confirmed cause of automatic fallback from 100GE to 40GE. An incompatible FEC setting is more likely to prevent a stable 100GE link or produce physical-layer errors. Check FEC when the 100GE interface remains down or accumulates errors, but first verify the detected transceiver type and operational rate.

Symptom-to-Cause Matrix

Final Confirmation

Run:

display interface brief
display interface 100GE 1/0/1
display transceiver interface 100GE 1/0/1 verbose
display license resource usage

The conversion is complete only when:

1. the licensed resource is active at the required scope;
2. the interface is operating in 100GE mode;
3. the physical and protocol states are UP;
4. and the detailed interface output reports:

Speed : 100000

The main diagnostic principle is:

The port reaches 100GE only after the correct SKU-specific software procedure has taken effect and both ends of the physical link support the same 100GE mode.

For a model-specific compatibility review, provide the complete switch SKU, VRP release, transceiver or cable PID, required distance and peer device through Network-Switch.com's Free CCIE Technical Support. Available transceiver categories can also be reviewed under Optical Transceiver Modules.

Sources

1. Huawei - License Control Items, S1720/S5700/S6700 Series Switches License Usage Guide
   Updated October 13, 2025.
   Open the Huawei document
2. Huawei - Installing Licenses, S1720/S5700/S6700 Series
   Updated October 13, 2025.
   Open the Huawei document
3. Huawei - Ethernet Interface Configuration Commands, V200
   Updated February 3, 2026. Covers assign port-type 100ge and port-type verification.
   Open the Huawei command reference
4. Huawei - S6730-S24X6Q Hardware Description
   Updated November 21, 2025. Documents V200R024C00 as the starting release for its 100GE RTU capability.
   Open the Huawei hardware page
5. Huawei - S6730-S48X6Q Hardware Description
   Updated November 21, 2025.
   Open the Huawei hardware page
6. Huawei - S6730-H24X6C-V2 Hardware Description, Part Number 02354HHV
   Updated July 6, 2026. Documents 40GE default operation and the optional 100GE RTU.
   Open the Huawei hardware page
7. Huawei - RTU Licenses for S5700, VRP V600
   Updated August 14, 2025. Covers active port-license in license view.
   Open the Huawei V600 RTU document
8. Huawei - Ethernet Interface Configuration Commands, VRP V600
   Updated March 11, 2026. Covers port mode 100GE interface and interface restart behavior.
   Open the Huawei V600 command reference
9. Community field case - "Any ideas to troubleshoot 100G link between Huawei switches?"
   Published January 18, 2024. Used only as a field symptom and reported resolution, not as an official compatibility matrix.
   Open the r/networking discussion