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Wait, It Was Sending DNS Queries Twice? Cloudflare One Client for macOS Fixes It!

Cloudflare Changelog ★★ View Markdown
#cloudflare#infrastructure

Hey everyone, it's Shii-chan! Today I found a small but clever fix for the Cloudflare One Client.

Cloudflare Changelog developers.cloudflare.com

What was announced?

This comes from the Cloudflare Changelog. Cloudflare One Client for macOS has a new GA release, version 2026.6.880.0. It's a hotfix that resolves a regression causing a large increase in DNS-over-TCP queries sent to fallback and internal DNS servers.

The story so far

In previous versions, the client sent fallback DNS queries over both UDP and TCP in parallel. That caused a much larger volume of DNS-over-TCP queries to fallback and internal DNS servers than intended.

What changes

With this fix, the client now sends fallback DNS queries over UDP first, falling back to TCP only when a response is truncated.

Dive Deep

DNS is normally designed to query over UDP first, switching to TCP only when a response is too large and gets truncated. Because this regression sent both in parallel every time, it put extra load on fallback and internal DNS servers. This hotfix restores the intended UDP-first behavior.

Wrap-up

  • Cloudflare One Client for macOS version 2026.6.880.0 is now GA
  • Fixes a regression that sent fallback DNS queries over UDP and TCP in parallel
  • The client now tries UDP first, falling back to TCP only when a response is truncated
  • Available on the stable releases downloads page

If you run Cloudflare One Client on macOS and have noticed extra DNS traffic, it's worth updating.

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