Jan 21 2014

Make apt-get use IPv4 instead of IPv6

It seems that Ubuntu/Debian (or perhaps other distros as well) prefer IPv6 DNS records instead of IPv4 when applicable and some times this results in loss of connectivity or similar problems.

I ran into this issue today while trying to update an old VPS with apt-get/aptitude. Specifically, security.ubuntu.com was being resolved in an unreachable IPv6 address and I had to wait some minutes for timeout every time.

Fortunately, there is an easy fix for this; you just have to edit the file located at: /etc/gai.conf which is the configuration for getaddrinfo(). There you have to uncomment line ~54 which reads: “precedence ::ffff:0:0/96  100”, and you are all set! (assuming that every other option is commented out by default as in my case).


  1. LoneSwimmer

    Thanks very much. When will the change take effect, next IP lease or would it be easier to just restart?

  2. Attila Fulop

    It works, thanks a lot. What does it actually do?

  3. HusseinOsama

    The correct way to do it is:

    Create a file in /etc/apt/apt.conf.d/99force-ipv4 or something with content:

    Acquire::ForceIPv4 “true”;

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