Link-local addresses for IPv6 DNS servers do not work for Linux systems

[openwrt]

Link-local addresses for IPv6 DNS servers do not work for Linux systems

[toreanderson]

Link-local DNS servers are perfectly valid, and has (in my experience) worked fine in NM since 2011. Assuming Ubuntu isn't shipping an ancient NM, the behaviour you're seeing must have some other reason. What's the contents of your /etc/resolv.conf file? What's the result of for NS in $(sed -n 's/^nameserver //p' /etc/resolv.conf); do dig @$NS . SOA; done?

[mamarley]

The only nameserver listed is 127.0.1.1, which is because Network Manager uses dnsmasq as a local DNS server. The output of the command is:

; <<>> DiG 9.10.3-P4-Ubuntu <<>> @127.0.1.1 . SOA ;; global options: +cmd ;; connection timed out; no servers could be reached

[toreanderson]

Ok, so this is a bug in dnsmasq and/or NetworkManager. The links will take you to the upstream bug reports I just filed.

For now you should be able to work around the issue by disabling dnsmasq (try sed -i /dns=dnsmasq/s/^/#/ /etc/NetworkManager/NetworkManager.conf).

[toreanderson]

Fixed in NetworkManager git master and nm-1.2 branches. I believe this odhcpd issue could be closed.