I'm running Debian 8 on a vServer. After installing docker and enabling IPv6 i noted something strange. I don't know if docker has anything to do with this, it's just that i noticed this problem after installing it.
My default route is configured to expire after ca. 1800secs. I actually vanishes after this timeout. This is when i (obviously) loose IPv6 connectivity.
root@wopr:~# ip -6 route xxxx:yyyy:zzz:xxxx::/64 dev eth0 proto kernel metric 256 fe80::/64 dev eth0 proto kernel metric 256 fe80::/64 dev br-5c1ce68ea951 proto kernel metric 256 fe80::/64 dev br-61f6bbfdbe87 proto kernel metric 256 [a lot more routed for my docker containers] default via fe80::1 dev eth0 proto ra metric 1024 expires 1259sec hoplimit 64
Why is it that the rout is configured to expire after 1800 s? Where can i configure this?
[edit 2016-05-14 16:08]
Adding a default route manually seems to work just fine. It stays put. But i need to have a non-expiring route after boot.
[edit 2016-05-14 16:13]
The machine is running on a KVM host hosted by netcup.de. It's using the virtio driver, as recommended by my provider.
root@wopr:~# cat /etc/network/interfaces auto lo iface lo inet loopback iface lo inet6 loopback auto eth0 iface eth0 inet dhcp iface eth0 inet6 static address xxxx:yyyy:zzz:xxxx::1 netmask 64 gateway fe80::1
root@wopr:~# virt-what kvm
[edit 2016-05-14 15:34]
It looks like i missed that
net.ipv6.conf.default.autoconf was set to 1. Now i added a file in /etc/sysctl.d to suppress this at boot:
root@wopr:~# cat /etc/sysctl.d/ipv6.conf net.ipv6.conf.default.accept_ra=0 net.ipv6.conf.default.autoconf=0 net.ipv6.conf.all.accept_ra=0 net.ipv6.conf.all.autoconf=0 net.ipv6.conf.eth0.accept_ra=0 net.ipv6.conf.eth0.autoconf=0