*) As for priority: It's not as low as you might imagine. The problem affects not just ifconfig but also ifup, which is indispensable. It also affects the "raise network interface" target at boot time, as triggered by "auto dummy0" directives in /etc/network/interfaces.
Symptom: :; ifup dummy0 Cannot find device "dummy0" Failed to bring up dummy0. This was hinted at in the original report but not emphasized. I emphasize it now. I mentioned ifconfig because it is the /simplest/ way to exhibit the bug. Feel free to change the headline of this bug to "ifup" (rather than "ifconfig") and transfer it to the ifupdown package (rather than net-tools) if you wish. This bug means that when I upgraded my machine remotely, it became unreachable, because the dummy0 interface carried the stable IP address that I was using. It took a great deal of work on my part to devise a workaround. *) In answer to your question: "until recently" means until I upgraded from xenial to bionic. I have another system still running xenial where ifconfig, ifup, and "raise network interface" all continue to work fine. The kernel version is exactly the same, 4.19.42; this may help you determine whether the regression is in user space and/or kernel space. On the other side of the same coin, I have yet another system with a squeaky clean bionic (installed ab_initio, not upgraded) that exhibits all the same problems with ifconfig, ifup, and "raise network interface". So it appears to be a bionic issue. I have no easy way to test the releases that came between xenial and bionic. All I know is that bionic is the latest LTS. It's supposed to be supported, and it's broken in a way that caused me a lot of grief. *) FURTHERMORE, there is nothing in the ifconfig man page to suggest that it is in any way deprecated. What's the deal? Choose your farce: -- Is it on double-secret probation? (Animal House) -- Doesn't it defeat the purpose of a deterrent if you keep it a secret? (Dr. Strangelove) -- Is perhaps the notice on display in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying "Beware of the Leopard"? (Hitchhiker's Guide) If it really is deprecated and unsupported, somebody should file a separate bug against the documentation. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to net-tools in Ubuntu. https://bugs.launchpad.net/bugs/1828749 Title: ifconfig dummy0 : Device not found Status in net-tools package in Ubuntu: Incomplete Bug description: 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 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/net-tools/+bug/1828749/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
