debian/kvm-ifup

   1 #!/bin/sh
   2
   3 switch=$(/sbin/ip route show |sed -nre 's/^default .* dev ([^ ]+).*$/\1/;T;p;q')
   4 /sbin/ip link set "$1" up promisc on
   5 test -d "/sys/class/net/$switch/bridge" && /sbin/ip link set "$1" master "$switch"