After I used "yum update" to upgrade my FC 6 xen guest to latest updates, after reboot, I no longer have a network device eth0. How reproducible: - Intel Core duo i386 machine, 4 GB ram - install Fedora 7 as host OS (dom0) - use original FC-6 ISO to install a fully virtualized Xen guest - host OS uses Xen default networking (bridge), when creating the xen guest, use virtual network - create xen guest with 10 GB file, 1000 MB ram, use default partition settings during guest install - it doesn't seem to matter whether you use manual IP settings or dhcp - complete initial fc6 configuration steps - enjoy networking - reboot fc6 xen guest - login to xen guest using ssh - enjoy networking - yum update -y - reboot fc6 xen guest - xen guest not reachable using ping or ssh - use virt-manager to open interactive view of fc6 xen guest - login, open terminal, type ifconfig - only loopback interface is listed I don't know which package causes the networking to go away. It appears it's not only the kernel. I tried to boot the xen guest using the 2.6.18-something kernel from the original install, but the network is still gone. When I use a paravirtualized Xen guest, using the exact procedure as described above, networking still works after the upgrade!!!
This might be related to Bug 247122: One way to check would be if you use virt-manager to add a second network card (as a "virtual network device"), do both network cards reappear and start working?
Fedora Core 6 is now end-of-life, so closing this bug out. Please test again on Fedora 7 or later, and open a new bug if your problem persists. Thanks.