On Di, 14.04.20 15:52, Fedora Development ML (devel@xxxxxxxxxxxxxxxxxxxxxxx) wrote: > On Tue, 14 Apr 2020 16:18:02 -0500 > Michael Catanzaro <mcatanzaro@xxxxxxxxx> wrote: > > > NetworkManager has three DNS backends: default (nss-dns, what we use > > currently), dnsmasq, and systemd-resolved. The default backend just > > does the wrong thing and cannot be fixed. When either dnsmasq or > > systemd-resolved is in use, NetworkManager will go ahead and do the > > right thing by telling dnsmasq/systemd-resolved which network > > interfaces should be used to resolve which hostnames. I consulted > > with the NetworkManager developers and they recommended > > systemd-resolved over dnsmasq, although I understand that dnsmasq is > > good too. > > Will the ability to turn off NetworkManager involvement in DNS in the > configuration file (None) still remain? I use a local caching DNS > server, and had to do that in order to allow it to run without > interference / override by NetworkManager. resolved has three modes: 1. If /etc/resolv.conf is a regular file, resolved will *consume* it for DNS configuration, and never change it or modify it or replace it. If this mode is selected arbitrary other programs that do DNS will talk directly to the provided DNS servers, and resolved is out of the loop. 2. Alternatvely, /etc/resolv.conf can be made a symlink to /run/systemd/resolve/stub-resolv.conf. That file is updated by resolved whenever DNS configuration changes. In it you'll find as DNS server the local host configured, where resolved is listening. In this mode other programs that do DNS will talk to resolved, and resolved propagates it to other DNS servers. 3. Alternatively /etc/resolv.conf can be made a symlink to /run/systemd/resolve/resolv.conf. That file is also updated by resolved whenever DNS configuration changes. In it you find a merged set of configured upstream DNS servers. In this mode programs that do DNS will talk directly to the upstream DNS servers, but resolved will still tell them which ones, based on all the information it has. In mode #1 resolved neither manages /etc/resolv.conf nor inserts itself into DNS resolution in any way. In mode #2 it manages *and* inserts itself into DNS resolution. In mode #3 it manages DNS resolution but will not insert itself to. NetworkManager natively supports informing resolved about DNS configuration changes, hence whenever NM discovers a new DNS server it tells resolved, which resolved then uses itself and writes it to /run/systemd/resolve/stub-resolv.conf and /run/systemd/resolve/resolv.conf. Long story short: we want to default to mode #2. But if you can chose mode #1 or #3 if you like, depending on whether you want to kick resolved out of managing resolv.conf or out of doing any DNS lookups for you at all. Lennart -- Lennart Poettering, Berlin _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
