1. brctl addbr net
2. ifconfig net 10.0.1.1/24 up
3. edit the dnsmasq.conf like dnsmasq.conf_pxe_boot
4. /etc/init.d/dnsmasq start
   • enable tftp server; then you should disable tftp-hpa service service tftp-hpa stop
   • configure the interface as your need
   • configure dhcp-sequential-ip get a ip in order
   • !! or you can use the command line to start the dnsmasq
     • /usr/sbin/dnsmasq -C /etc/dnsmasq.conf -x /var/run/dnsmasq/dnsmasq.pid -u dnsmasq -r /var/run/dnsmasq/resolv.conf -7 /etc/dnsmasq.d,.dpkg-dist,.dpkg-old,.dpkg-new --local-service
     • dnsmasq --strict-order --bind-interfaces --conf-file= --listen-address 10.0.1.1 --dhcp-range 10.0.1.2,10.0.1.254 --dhcp-lease-max=253 --dhcp-no-override --except-interface=lo --interface=net --dhcp-sequential-ip --dhcp-leasefile=/var/lib/misc/dnsmasq.lxcbr0.leases --dhcp-authoritative
     • dnsmasq --strict-order --bind-interfaces --conf-file= --listen-address 10.0.1.1 --dhcp-range 10.0.1.2,10.0.1.254 --dhcp-lease-max=253 --dhcp-no-override --except-interface=lo --interface=net --dhcp-sequential-ip --enable-tftp --tftp-root=/var/lib/tftpboot --dhcp-match=set:IPXEBOOT,175 --dhcp-option=tag:!IPXEBOOT,67,undionly.kpxe --dhcp-option=67,pxelinux.0 --dhcp-leasefile=/var/lib/misc/dnsmasq.lxcbr0.leases --dhcp-authoritative
   5. Ipxe boot test !!! PXEBOOT conf is not here! qemu-system-x86_64 --enable-kvm -cpu host -m 2G -net nic -net tap,script=/etc/ifup,downscript=/etc/ifdown example for /etc/qemu-ifup

#!/bin/sh
set -x

switch=net

if [ -n "$1" ];then
 #       /usr/bin/sudo /usr/sbin/tunctl -u `whoami` -t $1
        /usr/bin/sudo /sbin/ip link set $1 up
        sleep 0.5s
        /usr/bin/sudo /sbin/brctl addif $switch $1
        exit 0
else
        echo "Error: no interface specified"
        exit 1
fi

/etc/qemu-ifdown

#!/bin/sh
set -x

switch=net

echo "Executing /etc/qemu-ifdown"
sudo /sbin/ip link set $1 down
sudo /sbin/brctl delif $switch $1
sudo /sbin/ip link delete dev $1

6. iptables conf for net

iptables -t nat -A POSTROUTING -s 10.0.1.0/24 ! -d 10.0.1.0/24 -j MASQUERADE -- enable net port forward:

iptables -t nat -A PREROUTING -p tcp -i eth0 --dport 587 -j DNAT \ --to-destination 10.0.3.100:587

nothing to be done else! & enjoy it!!!