[root@localhost scripts]# sh network-bridge start Link veth is missing. This may be because you have reached the limit of the number of interfaces that the loopback driver supports. If the loopback driver is a module, you may raise this limit by passing it as a parameter (nloopbacks=); if the driver is compiled statically into the kernel, then you may set the parameter using loopback.nloopbacks= on the domain 0 kernel command line. [root@localhost scripts]# cat /boot/grub/menu.lst timeout 5 color black/cyan yellow/cyan shade 1 viewport 3 2 77 22 splashimage (hd0,0)/boot/grub/splash.xpm.gz default 0 title xen0 kernel (hd0,0)/boot/xen.gz dom0_mem=512000 module (hd0,0)/boot/vmlinuz-xen0 root=/dev/sda1 loopback.nloopbacks=50 ro title linux kernel (hd0,0)/boot/vmlinuz root=/dev/sda1 resume=/dev/sda7 initrd (hd0,0)/boot/initrd.img