I just upgraded a Xen host system from FC5 to FC6, and with that I lost networking... When I boot the system without starting the xend service, networking is fine. I have removed all iptables rules, so there is just "-j ACCEPT" for INPUT, OUTPUT and FORWARD chains. Everything is A-OK. When I start the xend service, it brings up the vif0.1 and the peth1 and connects them with xenbr1. Then I lose all connectivity. Atfer that, I can ifup and ifdown all day, play with brctl and whatnot - nothing seems to help but rebooting the system. I even tried removing all xen software, remove the config directory, reboot the system and then installing the whole thing again - to get the default configs. And before that, my configs were pretty straight-forward - nothing fancy. I keep thinking I overlooked something obvious... Any hints? --- Cheers, Kenneth