** Description changed: + [Impact] + Ubuntu users who make use of IPv4 link-local addresses. + + [Test case] + 1) Add 'link-local: [ ipv4 ]' to the netplan configuration. + 2) Run 'sudo netplan apply' + + [Regression Potential] + Enabling link local means additional addresses are available on the system, usually in the form "169.254.XXX.XXX". This is, in effect, a potential security issue if it is enabled on untrusted networks (it gives systems a fairly well known, discoverable IP address as attack surface). This is not considered a regression from previous releases of Ubuntu given that avahi has been available on desktop, with the same potential issue. The availability of extra addresses might however mean that the system is considered online or reachable via the additonal addresses earlier than previously possible, which may lead to confusion for the user. + + --- + Per https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1717983, link- local address support was previously handled via integration between avahi-autoipd and dhclient. systemd-networkd does not invoke dhclient. It also has direct support for configuring link-local ipv4 addresses. But this support is not enabled by default. It should be possible for a system configured via netplan to make use of link-local ipv4 addresses, without needing to configure systemd-networkd directly. Historically we do not turn on link-local ipv4 support automatically on servers (avahi-autoipd not installed by default), and we use link-local addresses only as a fallback when dhcp gives no response. So this should likely not be enabled by default, but instead be exposed as an additional configuration option in netplan yaml.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1771704 Title: support for ipv4 link-local addressing To manage notifications about this bug go to: https://bugs.launchpad.net/netplan/+bug/1771704/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
