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Rubygems access via IPV6

Sean's Avatar


05 Mar, 2019 04:42 PM


I am posting in followup to this thread closed in July 2018 regarding access to install/update rubygems over IPV6:

Is there a place to monitor progress on this? I had not encountered this until my desk was moved to another location where the local dns resolvers are configured (properly) to prefer IPV6 lookups. I have had to reconfigure my workstation so that glibc's getaddrinfo() prefers IPV4 lookups first in order to install/update gems.

It would seem that is publishing AAAA dns records but the webserver is not answering on this address:
$ ping6
PING (2a04:4e42::70)) 56 data bytes
--- ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 1999ms

Versus using IPV4:
$ ping
PING ( 56(84) bytes of data.
64 bytes from ( icmp_seq=1 ttl=54 time=25.2 ms
64 bytes from ( icmp_seq=2 ttl=54 time=25.2 ms
--- ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 25.259/25.273/25.287/0.014 ms

Can I suggest that the issue be fixed in one of two ways -
1. stop publishing AAAA dns records
2. configure the servers to answer to IPV6

If there is a better place to track this issue, please post a link that I can check up on every so often. Thank you kindly!

  1. 1 Posted by Domon on 13 May, 2019 05:45 AM

    Domon's Avatar

    I'm experience the same issue.

    I really hope could either support IPv6 or remove the IPv6 DNS record.


    Update: I restarted my computer and it works now. 

    > ping6
    PING6(56=40+8+8 bytes) [...] --> 2a04:4e42::70
    16 bytes from 2a04:4e42::70, icmp_seq=0 hlim=55 time=47.723 ms
    16 bytes from 2a04:4e42::70, icmp_seq=1 hlim=55 time=43.885 ms
    16 bytes from 2a04:4e42::70, icmp_seq=2 hlim=55 time=43.465 ms
    16 bytes from 2a04:4e42::70, icmp_seq=3 hlim=55 time=42.693 ms
    16 bytes from 2a04:4e42::70, icmp_seq=4 hlim=55 time=46.918 ms
  2. Support Staff 2 Posted by sonalkr132 on 13 Jul, 2020 07:47 AM

    sonalkr132's Avatar


    Sorry about the delay in response here. Can you please confirm if this is still an issue? If yes, I would like to forward some debugging info about your host/IP to the Fastly team.

    Thank you for your patience.

  3. 3 Posted by Braxton on 25 Aug, 2020 02:26 AM

    Braxton's Avatar

    Signing up just to comment. Yes @sonalkr132, this is still an issue.

  4. Support Staff 4 Posted by sonalkr132 on 25 Aug, 2020 06:12 AM

    sonalkr132's Avatar

    Hi Braxton,

    Thank you for reaching out. It would be very helpful if you can take some to run some commands for debugging info. Specifically, what is the output of the following commands when running from the host which has IPv6 connection issue to

    $ wget -6
    $ wget -6
    $ traceroute 2a04:4e42::70
    If you are feeling particularly generous, please add send pcap file for requests to over IPv6 as well. You can use tshark -i any -f "host" -w rubygems.pcap or sudo tcpdump -i any host -w rubygems.pcap
  5. 5 Posted by Braxton on 27 Sep, 2020 04:38 AM

    Braxton's Avatar

    Hi there,

    Thanks for getting back to me. Let's get this sorted out and fixed! The output from what you requested follows:

    $ wget -6


    --2020-09-26 23:18:32-- Resolving ( 2a04:4e42::70 Connecting to (|2a04:4e42::70|:80... failed: Operation timed out. Retrying.

    --2020-09-26 23:19:49-- (try: 2) Connecting to (|2a04:4e42::70|:80... failed: Operation timed out. Retrying.

    --2020-09-26 23:21:08-- (try: 3) Connecting to (|2a04:4e42::70|:80... failed: Operation timed out. Retrying.


    $ wget -6


    --2020-09-26 23:18:55-- Resolving ( 2606:4700::6810:4552, 2606:4700::6810:ad66 Connecting to (|2606:4700::6810:4552|:80... failed: Operation timed out. Connecting to (|2606:4700::6810:ad66|:80... failed: Operation timed out. Retrying.

    --2020-09-26 23:21:30-- (try: 2) Connecting to (|2606:4700::6810:4552|:80... failed: Operation timed out.


    $ traceroute 2a04:4e42::70


    traceroute: unknown host 2a04:4e42::70

    The pcap file returned the following (and is attached)

    21 packets captured 173315 packets received by filter 0 packets dropped by kernel

    Let me know what else I can share to get this fixed!

  6. 6 Posted by Braxton on 27 Sep, 2020 04:54 AM

    Braxton's Avatar

    To further clarify that the problem stems from the IPv6 protocol, I've included my terminal output for installing a gem with IPv6 enabled and disabled.


    $ gem install foreman

    ERROR: Could not find a valid gem 'foreman' (>= 0), here is why: Unable to download data from - timed out (


    $ networksetup -setv6off Wi-Fi

    $ gem install foreman Successfully installed foreman-0.87.2 Parsing documentation for foreman-0.87.2 Done installing documentation for foreman after 0 seconds 1 gem installed

  7. Support Staff 7 Posted by sonalkr132 on 27 Sep, 2020 05:01 AM

    sonalkr132's Avatar
    $ wget -6
    Connecting to (|2606:4700::6810:4552|:80... failed: Operation timed out.

    This is a kind of litmus test to identify the reason for the IPv6 issue. This command not working generally means the issue in your network (and not fastly/ You can try wget -6, it will timeout as well.
    The next step for you would be to further debug what is broken in your IPv6 network. I am assuming your host has an interface with IPv6 address (check ip addr), which is a prerequisite for any IPv6 issue. Perhaps try ping6 and see if that is working. Please do let us know about your finding or if you need help debugging this in your network.
    As of why "most" things work for you but gem install .. timeout, please check this pull request.

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