Why apt-get update fail to connecting to dl.google.com?

Question

My Ubuntu is 14.04.

I try to update my packages by:

sudo apt-get update

Then it stuck at

100% [Connecting to dl.google.com (203.208.40.46)]

for several minutes. It is quite annoying.

I try to set a timeout for the connections How to lower wait time for repository updates.

After several seconds, it failed and end the process.

Err http://dl.google.com stable InRelease                               

Err http://dl.google.com stable Release.gpg       
  Cannot initiate the connection to dl.google.com:80 (2401:3800:4002:802::1005). - connect (101: Network is unreachable) [IP: 2401:3800:4002:802::1005 80]
Reading package lists... Done
W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/InRelease  

W: Failed to fetch http://build.openvpn.net/debian/openvpn/stable/dists/trusty/InRelease  

W: Failed to fetch http://build.openvpn.net/debian/openvpn/stable/dists/trusty/Release.gpg  Unable to connect to build.openvpn.net:http:

W: Failed to fetch http://ppa.launchpad.net/neovim-ppa/stable/ubuntu/dists/trusty/main/binary-amd64/Packages  404  Not Found

W: Failed to fetch http://ppa.launchpad.net/neovim-ppa/stable/ubuntu/dists/trusty/main/binary-i386/Packages  404  Not Found

W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release.gpg  Cannot initiate the connection to dl.google.com:80 (2401:3800:4002:802::1005). - connect (101: Network is unreachable) [IP: 2401:3800:4002:802::1005 80]

W: Some index files failed to download. They have been ignored, or old ones used instead.

My location is China. I have Shadowsocks SOCKS5 system proxy and OpenVPN connecting to the same VPS server. I have tried turning off them both separately and together, but it did not work.

I wonder why this happen and how do I tackle it?

---update---

I could download the provided by @JonasCz.

Solution

When I have this problem, I disable IPv6 in Ubuntu and that fix the problem, in order to do that, please follow these steps:

To disable IPv6, you have to open /etc/sysctl.conf using any text editor and add the following lines at the end:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

If IPv6 is still enabled, then the problem is that sysctl.conf is still not activated.

In that case, open a terminal(Ctrl+Alt+T) and type the command:

sudo sysctl -p

The output will be very similar to these 3 lines:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

After that, execute:

$ cat /proc/sys/net/ipv6/conf/all/disable_ipv6

If you see 1 in the output, then IPv6 has been successfully disabled.

1

Hope this helps.

Comments

[JonasCz]

Are you sure your proxy / VPN is working correctly ? Both google.com and openvpn.net are failing, so my guess is that it's because of china's blocks on these. What do you get when you visit dl.google.com/linux/chrome/deb/dists/stable/Release.gpg in a web browser ?

[Penghe Geng]

This fixed my similar issue perfectly. Mine is Ubuntu 16.04.3 LTS.

[galoget]

Nice! Good to hear that. =D

[galoget]

Glad to know it worked for you @SiqingYu

[Ssuching Yu]

@galoget Hey guy, I found that disabling IPv6 slows down my apt download speed, so I enabled it again. Is there any workaround?

[galoget]

@SiqingYu, I always used the solution posted here, you can try this Using IPv4 or IPv6 for apt, hope this works.