I just encountered this issue upgrading Ubuntu MATE from 22.04 to 22.10. After the update, I had no network connectivity, and /etc/resolv.conf was symlinked to /run/systemd/resolve/stub-resolv.conf. I changed that to /run/systemd/resolve/resolve.conf, and my system is able to make connections once again. My system is running NetworkManager, and the only active connection is Docker0.
/run/systemd/resolve/stub-resolv.conf: nameserver 127.0.0.53 options edns0 trust-ad search DOMAINS /run/systemd/resolve/resolv.conf nameserver 192.168.2.1 nameserver 1.1.1.1 nameserver 1.0.0.1 search DOMAINS -- 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/1774632 Title: The symbolic link /etc/resolv.conf points to the wrong file by default Status in systemd package in Ubuntu: Confirmed Bug description: When using nslookup for local machine names, the local DNS was being ignored (not queried) and none of the local machines could be found. After much research and digging, it was discovered that the cause was the incorrect symbolic link /etc/resolv.conf file. The default install caused systemd-resolve to configure the link to point to the stub file: /etc/resolv.conf -> ../run/systemd/resolve/stub-resolv.conf Reomving that link and pointing it to the correct file solved the DNS lookup issue. The correct link looks like this: /etc/resolv.conf -> /run/systemd/resolve/resolv.conf Steps used to test the bug before fixing the link is to perform an nslookup on a local (non FQDN) machine that is in your local DNS (my router is my DNS server for this case) Here is an example of the incorrect output: $ nslookup web1 Server: 127.0.0.53 Address: 127.0.0.53#53 ** server can't find web1: SERVFAIL Switching the symbolic link solves the problem. Here is my solution: $ sudo rm -f /etc/resolv.conf $ sudo ln -s /run/systemd/resolve/resolv.conf /etc/resolv.conf After switching the symbolic link, the nslookup functions properly. $ nslookup web1 Server: 192.168.1.1 Address: 192.168.1.1#53 Name: web1 Address: 192.168.1.107 ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: systemd 237-3ubuntu10 ProcVersionSignature: Ubuntu 4.15.0-22.24-generic 4.15.17 Uname: Linux 4.15.0-22-generic x86_64 ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Fri Jun 1 05:28:41 2018 InstallationDate: Installed on 2018-01-20 (131 days ago) InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64 (20180105.1) MachineType: Dell Inc. Inspiron 5755 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-22-generic root=UUID=7fe151d3-4033-4903-b356-341d9f16e124 ro acpi=force SourcePackage: systemd UpgradeStatus: Upgraded to bionic on 2018-04-28 (33 days ago) dmi.bios.date: 08/27/2015 dmi.bios.vendor: Dell Inc. dmi.bios.version: A08 dmi.board.name: 0VY15F dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 8 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: A08 dmi.modalias: dmi:bvnDellInc.:bvrA08:bd08/27/2015:svnDellInc.:pnInspiron5755:pvrA08:rvnDellInc.:rn0VY15F:rvrA00:cvnDellInc.:ct8:cvrA08: dmi.product.name: Inspiron 5755 dmi.product.version: A08 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1774632/+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