Apparently, I've done a stupid thing and forgot my Ubuntu Server in AWS is Server 14. I've upgraded the ubuntu to 16.04 a few months back, but forgot that it's supposed to be still Ubuntu Server 14.
So I followed the guide https://docs.aws.amazon.com/vpc/latest/userguide /vpc-migrate-ipv6.html and followed the steps in Ubuntu Server 16. This got me locked out of my own server, and no matter what I tried (rebooting, assigned new private IP, tried pinging from other servers in the same subnet), I still can't get in. SSH ends up in Operation timed out. I've locked myself out. I even tried creating an AMI and launch the image into a new instance but still it won't work, maybe because the network interfaces files are backed up into the image as well? What can I do to regain access to my server? -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ifupdown in Ubuntu. https://bugs.launchpad.net/bugs/1013597 Title: No default route for stateful DHCPv6 Status in ifupdown package in Ubuntu: Fix Released Status in ifupdown source package in Precise: Won't Fix Bug description: The default route cannot be provided via DHCPv6, it must be obtained from router advertisements. However, when using the dhcp method for inet6 in /etc/network/interfaces (e.g. "iface eth0 inet6 dhcp"), ifup will set net.ipv6.conf.<IFACE>.accept_ra=0, resulting in no default route for IPv6. Instead, it should explicitly set accept_ra=1. A workaround is to set it in a post-up script. However, Linux apparently only sends router solicitations when the interface is brought up, so if unsolicited RA:s are infrequent the host will be without a default route until the next RA. Another problem is that when bringing the interface down on dual-stack hosts, there will be a long timeout. This is because bringing down IPv4 also brings the interface link down, and afterwards dhclient cannot release the DHCPv6 lease due to the link being down ("RTNETLINK answers: Cannot assign requested address"). The workaround is to bring the link back up before bringing IPv6 down. So the workarounds (which obviously should not be needed) for a dual- stack dhcp client look like this: iface eth0 inet dhcp iface eth0 inet6 dhcp up sysctl net.ipv6.conf.$IFACE.accept_ra=1 pre-down ip link set dev $IFACE up To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/1013597/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
