Message 2 of 2: This is easy to use and/or test ifup dummy0 and ifdown dummy0
You don't need to know the complexities of the motivation for why this is important; the test case is very simple. In the context of the ifupdown package, this requires putting a stanza like this in /etc/network/interfaces or /etc/network/interfaces.d/dummy: auto dummy0 iface dummy0 inet static netmask 255.255.255.255 address 10.10.2.105 Then the static dummy interface (a) should come up automagically at boot time, and can be further controlled by :; ifup dummy0 :; ifdown dummy0 Desired behavior: It should just work. Observed behavior: :; ifup dummy0 Cannot find device "dummy0" Failed to bring up dummy0. Highly informative workaround: :; ip link add dummy0 type dummy That command works, and makes the problem go away permanently. The ifup and ifdown commands 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. See the detailed workaround script attached previously. FWIW the ifconfig command exhibits all the same misbehavior; net-tools and ifupdown are affected in the same way, but remarkably enough the ip command (from the iproute2 package) is apparently not affected by this bug. -- 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/ifupdown/+bug/1828749/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs