Tested...
Disable IPv6...
1) Disable Kernel Scope...
# nano /etc/sysctl.conf
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.<interface>.disable_ipv6 = 1
(Where <Interface> is the network adapter, eth0, ens33, etc.)
# sysctl -p
# reboot
2) Disable Grub Scope...
# nano /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT add 'ipv6.disable=1'
# update-grub2
# reboot
3) Disable Via Black List...
# echo 'blacklist ipv6' >> '/etc/modprobe.d/blacklist.conf'
# reboot
4) Test Disable Of IPv6...
# reboot
# test -f /proc/net/if_inet6 && echo "Running kernel is IPv6 ready"
Then after tried apt-get update which was working before IPv6 disable, and it just hangs. Even after enable again of IPv6, apt-get update still hangs...
# apt-get update
0% [Connecting to ftp.us.debian.org (128.30.2.26)] [Connecting to security.debian.org (128.61.240.73)]
Also tried...
# apt-get -o Acquire::ForceIPv4=true update
0% [Connecting to ftp.us.debian.org (128.30.2.26)] [Connecting to security.debian.org (128.61.240.73)]
After about 15 minutes, process aborts reporting network connection failed?
Err:1 http://security.debian.org/debian-security stretch/updates InRelease
Could not connect to security.debian.org:80 (128.61.240.73), connection timed out [IP: 128.61.240.73 80]
Err:2 http://ftp.us.debian.org/debian stretch InRelease
Could not connect to ftp-chi.osuosl.org:80 (64.50.236.52), connection timed out Could not connect to debian.gtisc.gatech.edu:80 (128.61.240.89), connection timed outuld not connect to ftp-nyc.osuosl.org:80 (64.50.233.100), connection timed out Unable to connect to ftp.us.debian.org:http: [IP: 208.80.154.15 80]
Err:3 http://ftp.us.debian.org/debian stretch-updates InRelease
Unable to connect to ftp.us.debian.org:http: [IP: 208.80.154.15 80]
Reading package lists... Done
W: Failed to fetch http://ftp.us.debian.org/debian/dists/stretch/InRelease Could not connect to ftp-chi.osuosl.org:80 (64.50.236.52), connection timed out Could not cect to debian.gtisc.gatech.edu:80 (128.61.240.89), connection timed out Could not connect to ftp-nyc.osuosl.org:80 (64.50.233.100), connection timed out Unable to conn to ftp.us.debian.org:http: [IP: 208.80.154.15 80]
W: Failed to fetch http://security.debian.org/debian-secur ... /InRelease Could not connect to security.debian.org:80 (128.61.240.73), connection ed out [IP: 128.61.240.73 80]
W: Failed to fetch http://ftp.us.debian.org/debian/dists/s ... /InRelease Unable to connect to ftp.us.debian.org:http: [IP: 208.80.154.15 80]
W: Some index files failed to download. They have been ignored, or old ones used instead.
Does not seem to be able to recover from issue, had to reinstall OS to get apt-get working again. At no time does any of the repos seem to be down, not internet access issues, reinstall of OS and not disabling IPv6, all sites not found, are found as expected.
Scheduled Maintenance: We are aware of an issue with Google, AOL, and Yahoo services as email providers which are blocking new registrations. We are trying to fix the issue and we have several internal and external support tickets in process to resolve the issue. Please see: viewtopic.php?t=158230