I ran into this today and after a lot of head-scratching, it just occurred to me that this is probably the expected behavior. systemd- network(5)'s IPv6AcceptRA section says (https://www.freedesktop.org/software/systemd/man/latest/systemd.network.html):
> Note that kernel's implementation of the IPv6 RA protocol is always disabled, regardless of this setting. Then I read this comment: https://unix.stackexchange.com/questions/759771/ubuntu-accept-ra-is-not- effective-with-sysctl-and-prevents-dhcp6-when-in- netplan#comment1448644_759791, quoted below: > It's for the in-kernel RA handler. Traditionally Linux has done IPv6 autoconfig (though not DHCPv6) without any userspace software at all, but its capabilities are limited. (Networkd actually sets it to 0 even if IPv6AcceptRA=true.) What possibly confused the readers (including me) was, systemd- network(5) does say: > Also see IP Sysctl in the kernel documentation regarding "accept_ra", but note that systemd's setting of 1 (i.e. true) corresponds to kernel's setting of 2. At the beginning, this paragraph made me think systemd-networkd sets `accept_ra` to 2 when `IPv6AcceptRA=yes`. But, no. Now I realized systemd-network(5) was merely using the kernel document to explain that `IPv6AcceptRA=yes`'s behavior is the same as `accept_ra=2`'s behavior (i.e, accepting RA messages even if forwarding is enabled), but systemd- networkd always sets `accept_ra=0` duo the the explanation of "Note that kernel's implementation of the IPv6 RA protocol is always disabled". -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1862481 Title: Cannot set accept-ra to 2, it keeps reseting it to 0 To manage notifications about this bug go to: https://bugs.launchpad.net/netplan/+bug/1862481/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
