Skip to content
CC Switch WikiUnofficial Community Wiki

cc-switch overrides DNS cache and resolves api.deepseek.com to 127.0.0.1 when enabled (Unexpected DNS hijacking behavior)

Quick fix

Disable proxy takeover in the affected application to restore network connectivity; cc-switch does not modify system DNS records.

Symptom

Section titled “Symptom”
Error output
When enabling cc-switch, it unexpectedly interferes with the local AD DNS (or system DNS cache/resolution), forcefully hijacking domains such as api.deepseek.com and platform.deepseek.com and resolving them to 127.0.0.1.

Cause

Section titled “Cause”

Users observed DeepSeek-related domains resolving to 127.0.0.1 after enabling cc-switch and suspected that cc-switch had hijacked DNS. However, code review found that cc-switch’s built-in proxy works by starting a local HTTP listener and modifying the proxy’s API base URL. This can cause a loopback URL to appear in the proxy configuration, but it does not cause public domains to resolve to a loopback address in nslookup. The issue is therefore more likely caused by rules in an external DNS filtering component, such as AdGuard or Active Directory DNS, rather than cc-switch directly modifying system DNS records.

Fix

Section titled “Fix”

  1. Disable proxy takeover in the affected application to continue using configuration switching without local HTTP routing.

Affected Versions

Section titled “Affected Versions”
Toolcc-switch
Version3.20
PlatformsWindows

Source Issues

Section titled “Source Issues”

This page is distilled from 3 real issues

FAQ

Section titled “FAQ”
Does cc-switch modify system DNS records?
According to code review, cc-switch does not modify system DNS records, the hosts file, or AdGuard / Active Directory DNS settings.
How can I check DNS resolution issues?
Use the nslookup command to check DNS resolution, for example: nslookup -type=A api.deepseek.com
Section titled “Related problems”
<thinking> tags output as body text in Claude CodeChanging the provider's apiFormat from openai_chat to anthropic, if supported upstream, can bypass inline <thinking> leakage.1 issues mergedProvider API Key Overwritten: After Codex Restart or SwitchUpgrade to cc-switch v4.0.0 or later to prevent provider keys from overwriting each other and restore the official login state.6 issues mergedmissing field `call_id`DeepSeek Responses rejected a Codex delegated task entry missing `call_id`; the issue did not confirm a user-side fix.1 issues merged

This is an unofficial community wiki with no affiliation to the cc-switch authors or the project itself. Its content is compiled from the project's public GitHub issues. This site distributes no software.