1. Please describe the problem: The Linux kernel loopback ('lo') interface does not have a link-local address. This is contrary to RFC 4291, "IP Version 6 Addressing Architecture", which says, "2.1. Addressing Model All interfaces are required to have at least one Link-Local unicast address (see Section 2.8 for additional required addresses)." I'd suggest generating a Link-Local Interface Identifier part of the address for the loopback interface using the RFC 7217, "A Method for Generating Semantically Opaque Interface Identifiers with IPv6 Stateless Address Autoconfiguration (SLAAC)", algorithm, as this algorithm has now become the default recommend algorithm for stable IIDs, per RFC 8064, "Recommendation on Stable IPv6 Interface Identifiers" Note that the fairly similar 'dummy' virtual interfaces do get a Link-Local address when you bring them up. 2. What is the Version-Release number of the kernel: 5.0.10-300.fc30.x86_64 I'm competent enough with C to read kernel code, but not to contribute fixes. Looking at the latest kernel.org net-next version of addrconf.c under the ipv6 directory, it seems that the loopback interface is treated as a special case by init_loopback(), rather than using addrconf_dev_config(), which looks to be where Link Local addresses are generated and configured for other types of interfaces. I've marked this as medium severity as one of the ideas behind all IPv6 enabled interfaces having at least one Link-Local address is so that IPv6 applications always have an IPv6 address on a link to use, even if the address can only be used to reach other devices on the link. In the case of the loopback interface, this could be for application testing purposes.
*********** MASS BUG UPDATE ************** We apologize for the inconvenience. There are a large number of bugs to go through and several of them have gone stale. Due to this, we are doing a mass bug update across all of the Fedora 30 kernel bugs. Fedora 30 has now been rebased to 5.2.9-200.fc30. Please test this kernel update (or newer) and let us know if you issue has been resolved or if it is still present with the newer kernel. If you have moved on to Fedora 31, and are still experiencing this issue, please change the version to Fedora 31. If you experience different issues, please open a new bug report for those.
*********** MASS BUG UPDATE ************** This bug is being closed with INSUFFICIENT_DATA as there has not been a response in 3 weeks. If you are still experiencing this issue, please reopen and attach the relevant data from the latest kernel you are running and any data that might have been requested previously.
This bug report was closed, however INSUFFICIENT_DATA keeps pestering me for information.