Public bug reported: Desired behavior: The ifconfig command should be able to deal with the dummy device. This worked fine until recently.
Observed behavior: :; ifconfig dummy0 dummy0: error fetching interface information: Device not found This problem appeared when I upgraded to bionic. Highly informative workaround: :; ip link add dummy0 type dummy That command works, and makes the problem go away permanently. The ifconfig command works fine after that. The ifup and ifdown commands also work fine after that. For convenient debugging, you can use the command: :; ip link del dummy0 type dummy which makes the problem come back. You can also experiment with dummy1 et cetera. Package ownership issues: Compare: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=909204 That report was filed against ippusbxd, which is almost certainly not the relevant package. For that matter, I have no idea whether the root cause is in the net-tools package or the kernel networking stack. All I know is the ip command plays nicely with the kernel while the ifconfig command does not. Notes: The kernel module for the dummy interface is preloaded in all situations described here. That's not the issue. An apport file is attached, to describe the environment. Also, since you asked: :; apt-cache policy net-tools net-tools: Installed: 1.60-26ubuntu1 Candidate: 1.60-26ubuntu1 Version table: *** 1.60-26ubuntu1 500 500 http://ubuntu.cs.utah.edu/ubuntu xenial/main amd64 Packages 100 /var/lib/dpkg/status :; lsb_release -rd Description: Ubuntu 16.04.6 LTS Release: 16.04 ** Affects: net-tools (Ubuntu) Importance: Undecided Status: New ** Attachment added: "apport file describing the system" https://bugs.launchpad.net/bugs/1828749/+attachment/5263315/+files/apport.net-tools.yuq36yqq.apport -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1828749 Title: ifconfig dummy0 : Device not found To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/net-tools/+bug/1828749/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
