----- Original Message ----- From: "Peter Stuge" <stuge-vlan@xxxxxxx> >> 2: vif0.0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue >> link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff > > This doesn't look like a very good ethernet address. Does that > matter? The interface in theory never generates any traffic. Any tcpdump's I've done, I haven't seen this MAC address. My understanding is this is a private non-multicast MAC address. If the redhat FC4 scripts don't seem to have propagated the 'ARP=no' configuration correctly (but I don't think it matters). The interface has no IP address. So it shouldn't matter. > Perhaps the xen interface drivers do tricks? In theory it's just a loopback style interface that communicates between the xen VM's (and in the case of vif0.0 it is paired with veth0 on the same machine). My understanding is that the frames will be received from the veth interface in the VM, and so they will get the MAC address from the VM interface (which is a valid unique value). Greg :-)