Help Center/ ModelArts/ Model Development/ Using Notebook for AI Development and Debugging/ Using Notebook Instances Online Through Code Server/ Code Server Network Requirements for Enterprise Users
Updated on 2026-07-14 GMT+08:00
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Code Server Network Requirements for Enterprise Users

To ensure the stability of Code Server within an enterprise intranet environment, the following requirements must be met:

Code Server Domain Dependencies

To ensure the proper operation of Code Server, network access permissions for the domains below must be granted. These domains are required for features such as the extension marketplace, resource loading, and remote development; disabling them will impact the usability of these features.

Domain

Purpose

authoring-modelarts-cnnorth4.huaweicloud.com

ModelArts platform domain (The example provided is for CN North-Beijing4; modify it according to your actual region).

vscode-remote+authoring-002dmodelarts-002dcnnorth4-002ehuaweicloud-002ecom.vscode-resource.vscode-cdn.net

VS Code remote development resource acceleration CDN (ModelArts platform).

openvsx.eclipsecontent.org

Open VSX content delivery/image domain, used to accelerate extension file (.vsix) downloads and static resource distribution.

img.shields.io

Periodically (or in real-time) pulls download metrics from the Visual Studio Marketplace API to generate project badges (for example, download counts, version numbers), fetching data in real-time and rendering it as images.

github.com

GitHub code hosting platform and original file access gateway.

raw.githubusercontent.com

GitHub raw file direct link service (used for direct access to code files).

badges.gitter.im

Generates Gitter chat room badge icons.

open-vsx.org

VS Code extension marketplace and registry (open-source alternative).

code.visualstudio.com

Official VS Code website (documentation, downloads, community, and more).

Code Server Network Troubleshooting

In an enterprise intranet environment, Code Server may encounter the following network faults. Below are the symptoms and their solutions.

Fault 1: WebSocket Connection Abnormality

When your browser attempts to establish a WebSocket connection with the Code Server backend, the relevant extensions fail to display.

Figure 1 Extensions not showing
Figure 2 Extensions showing normally

The following error appears when opening the browser's developer tools window:

Invalid frame header
Figure 3 Browser error message

Fault 2: Error Creating or Opening Jupyter Notebook Files

An error occurs when creating or opening a Jupyter file within Code Server.

  • Create a Jupyter file: 
    Command 'Create: New Jupyter Notebook' resulted in an error
    Figure 4 Creating a Jupyter file
    Figure 5 Error creating a Jupyter file
  • Open a Jupyter file: 
    Unable to open 'xxx.ipynb'
    Figure 6 Error opening a Jupyter file

Possible Root Causes and Solutions

The table below describes the possible causes and solutions.

Possible Cause

Description

Solution

Protocol mismatch

WebSocket connections require the server to strictly adhere to the RFC 6455 protocol. The error message indicates:

  • The header format of the data frame returned by the server does not conform to the WebSocket standard.
  • The proxy server or TLS layer may have modified the data packets (common in enterprise network environments).

Check whether enterprise proxy servers or TLS middleware (for example, Nginx or Squid) are performing non-standard processing on WebSocket traffic. Any such modification features must be disabled.

Enterprise firewall / CDN interference

Firewalls or CDNs within the enterprise network may intercept or attempt to optimize WebSocket traffic, leading to connection abnormalities.
  • Firewall configuration
    • Confirm that the firewall permits WebSocket traffic (protocol types WS or WSS).
    • Check if the Upgrade: websocket request header is being blocked.
  • CDN configuration
    1. Disable auto-compression (such as Gzip or Brotli) on the CDN to prevent WebSocket data frame modification.
    2. Ensure the CDN supports WebSocket protocol passthrough.
  • NAT timeout adjustment: Adjust the NAT timeout duration to ≥ 1,800 seconds (30 minutes) to prevent connections from being terminated due to timeouts.

Proxy network abnormality

The proxy server might not be correctly forwarding WebSocket requests, or there may be a Man-in-the-Middle (MITM) encryption causing protocol conflicts.

Ensure that the proxy server explicitly supports WebSocket protocol passthrough.
Parent Topic: Using Notebook Instances Online Through Code Server