On 13/10/2021 20:06, J Martin Rushton via CentOS wrote: > If you just want to tell NM to clear off and leave your resolv.conf > alone do the following: I might possibly be able to set up a workaround based on that, but it's not what I really want. Ideally I want NetworkManager to update resolv.conf, but only if it actually set up a new connection and/or got new information. Which is what it seemed to do in the past, but then something changed... - Toralf > > 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://eur04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.centos.org%2Fmailman%2Flistinfo%2Fcentos&data=04%7C01%7Ctoralf.lund%40pgs.com%7C8d1517edd2f44e2b991f08d98e743008%7C51d05d6147e9480b93b298dc84f1ed06%7C0%7C0%7C637697452053567265%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=HH613vBZFHsnsTuJJi52I1%2FSM8Z22U1gVe%2BSsAqOPrg%3D&reserved=0 >> >