Mac OSX (10.8.X) scripts for QEMU/KVM bridged networking with nat on en1.

qemu-ifdown

#!/bin/bash
echo "Executing /etc/qemu-ifdown"
echo "Bringing TAP interface down"
ifconfig $1 down
echo "Removing interfaces"
ifconfig bridge0 deletem en1 deletem $1
echo "Bring down bridge"
ifconfig bridge0 down
echo "Removing bridge"
ifconfig bridge0 destroy
sysctl -w net.link.ether.inet.proxyall=0
sysctl -w net.inet.ip.forwarding=0
sysctl -w net.inet.ip.fw.enable=0
echo "Removing ipfw rule"
ipfw del `ipfw list | grep 'ip from any to any via en1' | sed -e 's/ .*//g'`
echo "Stop natd"
killall -9 natd

qemu-ifup

#!/bin/bash
echo "Executing /etc/qemu-ifup"
echo "Creating bridge"
sysctl -w net.link.ether.inet.proxyall=1
sysctl -w net.inet.ip.forwarding=1
sysctl -w net.inet.ip.fw.enable=1
ifconfig bridge0 create
echo "Bringing up $1 for bridged mode"
#Get the number of interface
num=`echo $1 | sed 's/tap//'`
ifconfig $1 192.168.2.1$num up
echo "Add $1 to bridge"
ifconfig bridge0 addm en1 addm $1
echo "Bring up bridge"
ifconfig bridge0 up
echo "Starting Natd on en1"
natd -interface en1
echo "Writing ipfw rule"
ipfw add divert natd ip from any to any via en1