If you just want to tell NM to clear off and leave your resolv.conf alone do the following: If you don't want it to touch the contents of the file then remove all DNSx= parameters from all ifcfg files and add PEERDNS=“no” instead. Now you are solely responsible for setting the content of /etc/resolv.conf yourself. You may also have to edit /etc/NetworkManager/NetworkManager.conf and add dns=none to the [main] section. On 13/10/2021 18:24, Toralf Lund wrote: > Hi > > Does here anyone know exactly when NetworkManager creates or is supposed > to create /etc/resolv.conf for a network connection? Is there a way I > can control it, or alternatively, is there a good way to debug the > functionality? > > I thought that there would simply be an update whenever a connection was > established, and an addresses/network info was received (if using DHCP), > and that the information would pretty much be left alone after that. > However, I've lately found that a new file gets written every few hours > even though there is no connection change (that I can detect), i.e. the > same link is up all along. Does anyone have any ideas why that might > happen? I thought at first that the updates could be linked to DHCP > lease renewal, but on closer inspection, that does not seem to be the > case. I don't see anything in the system log related to networking at > the points where a new file gets written. > > I get the above behaviour for my home Wifi net. It seemed to start after > I switched to a new router, but that might be coincidental. It's a > problem for me because I'm also using "commercial" VPN software (not > integrated with NetworkManager) that will create it's own resolv.conf > file; it replaces data e.g. from Network Manager when VPN is enabled, > and restores it on disable. If NetworkManager "refreshes" the > information in the mean time, the DNS config for VPN is lost, and the > link doesn't work as expected... > > This is on a CentOS 7 system with all the latest updates. > > - Toralf > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos -- J Martin Rushton MBCS