https://bugzilla.novell.com/show_bug.cgi?id=814033 https://bugzilla.novell.com/show_bug.cgi?id=814033#c0 Summary: Guest is set up with User Mode Networking changes to regular NAT networking spontaneously Classification: openSUSE Product: openSUSE 12.3 Version: Final Platform: x86-64 OS/Version: openSUSE 12.3 Status: NEW Severity: Major Priority: P5 - None Component: KVM AssignedTo: kvm-bugs@forge.provo.novell.com ReportedBy: tonysu@su-networking.com QAContact: jdouglas@suse.com Found By: --- Blocker: --- User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:19.0) Gecko/20100101 Firefox/19.0 Scope of issue: Unknown. Although slirpvde is available, it looks to me that it's likely that QEMU-KVM has its own slirp code to support User Mode Networking. If so, then this problem is limited to QEMU-KVM. Background: This applies <only> to the recently integrated User Mode Networking. Do not confuse with traditional (other types of) networking. Setup Description, why User Mode Networking: As expected, when a Guest is created without any virtual networks configured on the Host, User Mode Networking is automatically invoked which implements slirp to setup an automatic NAT network which has advantages binding to whatever active network interface which may exist unlike convential virtual networks which typically need to bind to a pre-configured br device which in turn is bound statically to a specified network interface (eg eth0). I have experimented binding a br device to multiple network interfaces (eg eth0 and wlan0) but does not function as hoped, which is automatic virtual networking on whichever interface is active. Problem: Although User Mode Networking can be setup easily enough, if at any time the configured Guest is launched on a Host with no active network connection, User Mode Networking is lost. The Guest automatically re-configures itself to look for a br device (traditional networking) and it seems that there is no possible way to re-configure for User Mode Networking, even launching from command line. Reproducible: Always Steps to Reproduce: 1. Start with a Host without a br device configured and no Virtual Network configured. 2. Create a Guest VM (any OS), which should include a NIC. I've been configuring a virtio network device, but it is unimportant, any selection is affected. 3. Launch the Guest 4. Verify the Guest has acquired a DHCP network address for eth0. Depending on the OS, you may have to manually configure in the Guest (eg CentOS). 5. Shutdown the Guest. 6. disable or physically unplug all network connections... 802.3 and wireless. 7. Boot Guest Actual Results: The steps to re-produce results in a system with no networking interface (not even to the Host). Shutdown the Guest and inspect the Guest configuration, if running virt-manager this is easy to do by inspecting the NIC properties, you will see that instead of User Mode Networking the NIC will be configured to connect to "specify network"

From this point on, the Guest VM is useless because no networking is possible. The existing NIC cannot be re-configured with User Mode Networking Removing and adding a replacement NIC cannot be configured with User-Mode Networking

User Mode Networking is permanently lost and unavvailable, even from the command line (invoking -net user). Expected Results: 1. Even with no active physical network connection, expect any type of NAT should support "local machine only" isolated network functionality which exists using VMware and Hyper-V 2. The NIC configuration for type of networking should not have changed simply because no physical network connection existed during a boot. 3. It seems that once a NIC has been configured to point to a pre-configured br device, User Mode Networking is no longer possible. Why? Am hoping this can be addressed. Am assigning this as "major" because although I'm intentionally attempting to work "disconnected" from my laptop, this problem would also affect a regularly configured KVM-QEMU Guest on a Server... If for some reason networking was lost during a boot, then all existing User Mode Networking configuration would be lost and irrecoverable. The only options then would be to configure traditional networking or pave and re-build the Guest. For what I'm doing on a laptop, User Mode Networking is a critical must. And, interestingly as I've described above there is no problem using VMware and Hyper-V using virtualized networking the same way. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.