The premis is that you have a network device with a "link local" (aka: "scopeid 0x20<link>") inet6 address.
In my case, "ifconfig enp4s0" shows a line like this: inet6 fe80::4687:fcff:fe9e:4ac7 prefixlen 64 scopeid 0x20<link> If your machine does NOT have such a line, then I must admit, I don't know how to produce one. Mine had it from default setup. If your machine DOES have an inet6 link local address, then (in a shell) run "host $(hostname)" and it is likely to return an inet (ipv4) address (that's just fine) AND the link local inet6 address. If your "host $(hostname)" doesn't give you any inet6 address, or gives you one with %network-name appended, then you might have a different version of "systemd" than 237-3ubuntu10.33 (as included in 18.04) -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1853669 Title: systemd resolves own hostname to link local ipv6 address Status in systemd package in Ubuntu: Incomplete Bug description: I've got an ethernet-device that only has a configured ipv4 address, and some auto-generated link-local (aka "scope link") ipv6 address. Any tool doing a DNS query (and /lib/systemd/systemd-resolved is the DNS-server listening on 127.0.0.53) for this host's hostname gets back two addresses: the correct ipv4 address, and a broken ipv6 address. Unlike on ipv4, it is possible for the same ipv6-address to be assigned to multiple devices, and therefore the address is only valid in the context of the eth-device. Now, if "ifconfig" shows "inet6 fe80::4687:fcff:fe9e:4ac7 prefixlen 64 scopeid 0x20<link>" then "fe80::4687:fcff:fe9e:4ac7" is NOT a connectable address, and syscall connect() typically fails with EINVAL. To make it a valid address, it needs to be suffixed with a "%" and the device name, like: fe80::4687:fcff:fe9e:4ac7%enp4s0 Either the resolver can return the link name attached to the address separated with a "%" char, or it needs to ignore link-local inet6 addresses. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1853669/+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
