IPv6 support

[whatUwant]

Is it possible to force youtube-dl to work only via IPv6?
It's impossible to access Youtube via IPv4 in China without a proxy or VPN service while accessing via IPv6 has not yet been banned.
I don't know if youtube-dl chose to access youtube via IPv6 by chance. A few days ago, youtube-dl seemed to be working fine with IPv6. But recently all downloads have failed. The error message is "urlopen error [Errno 104] Connection reset by peer". I'm pretty sure there is nothing wrong with my IPv6 connectivity. The only explanation I can come up with is that youtube-dl is trying to access youtube via IPv4 right now.

[phihag]

Currently, youtube-dl simply picks whatever your DNS/IP stack thinks is available, and for youtube, that's IPv6. I'll look into it, but may need to contact you personally to reproduce the issue, since I don't have any servers in China at the moment. Can you send me an email with ways to contact you (by icq/Jabber/email/phone, whatever)?

I suspect a DNS-level issue could be the problem. What do you get if you run

dig youtube.com AAAA

on your system?

[whatUwant]

Hello Philipp.
When I ran "dig youtube.com AAAA" I got this

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-20.P1.el5 <<>> www.youtube.com AAAA
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27062
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;www.youtube.com.               IN      AAAA

;; ANSWER SECTION:
www.youtube.com.        23190   IN      CNAME   youtube-ui.l.google.com.
youtube-ui.l.google.com. 868    IN      CNAME   youtube-ui-china.l.google.com.

;; AUTHORITY SECTION:
l.google.com.           600     IN      SOA     ns2.google.com. dns-admin.google.com. 1502868 900 900 1800 60

;; Query time: 118 msec
;; SERVER: 202.120.127.220#53(202.120.127.220)
;; WHEN: Sun Nov 11 05:00:31 2012
;; MSG SIZE  rcvd: 148

I also queried Google's dns server 2001:4860:4860::8888

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-20.P1.el5 <<>> www.youtube.com AAAA
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 23866
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.youtube.com.               IN      AAAA

;; ANSWER SECTION:
www.youtube.com.        300     IN      AAAA    ::908a:1a45:0:0

;; Query time: 39 msec
;; SERVER: 2001:4860:4860::8888#53(2001:4860:4860::8888)
;; WHEN: Sun Nov 11 05:17:26 2012
;; MSG SIZE  rcvd: 61

I'm afraid I was wrong about my IPv6 connectivity.
It seems that dns poisoning has already been effective on IPv6.

[whatUwant]

I can access Youtube via HTTPS in Firefox if I manually associate correct IPv6 addresses with youtube domain names in /etc/hosts. But still, youtube-dl is not working.

[meteormatt]

If you use IPv6, you should use IPv6's DNS.
For example, Google's dns server 2001:4860:4860::8888
IPv4's DNS will response IPv4 address first.

[phihag]

@meteormatt Your browser (and youtube-dl) will send A and AAAA queries in parallel, so it doesn't matter which DNS server you choose.

[dfc]

I have a ipv6 tunell through huricane electric. Youtube downloads are much quicker via the tunnel than when I use straight ipv4 via my ISP. I would be interested in yt-dl having a ipv6 switch. I am currently trying to get /etc/gai.conf to prefer ipv6 for google and youtube. However that is not the most portable solution.

[SylvainBoilard]

I second that, an option to force youtube-dl to use a particular version of the IP protocol would come in handy. I’m on a network where IPv6 connectivity is obtained through an IPv6 tunnel with a much lower data rate than what is available using IPv4, so using IPv6 to download large contents is impractical and might get annoying for other users.

[haasn]

I second that the protocol should be configurable, for similar reasons. My go-to workaround as of now is to use wget -4 -O filename $(youtube-dl -g link) but it's of course a bit bothersome to type that every time I want to download something, especially since I have to assign a filename manually.

It would be great if you could add flags like wget's -4 and -6 options manually. Alternatively, it would be great to be able to use wget in combination more easily (which is also good for stuff like --timeout, --limit-rate among other useful flags).

[kaimi]

-4 / -6 switches would be really great 👍

[phihag]

-4 and -6 switches are present in youtube-dl 2015.01.10.1 and newer. See our FAQ if you need help updating.

[kaimi]

Nice job, thanks!