virtualbox.org

hi,
host: windows xp, guest: ubuntu 12.04
i have two nic adapter: NIC1 attach to bridge adapter, name bind physical network card(Realtek PCI),
NIC2 attach to bridge adapter, name bind physical network card(Intel(R) PRO/1000 MT Desktop)

it display eth0 and eth1 on guest ubuntu, i use TC script to limit eth1 bandwidth, TC script as below:
/sbin/tc qdisc del dev eth1 root 2> /dev/null
/sbin/tc qdisc add dev eth1 root handle 1: htb default 20
/sbin/tc class add dev eth1 parent 1: classid 1:1 htb rate 6160000bit ceil 6160000bit
/sbin/tc class add dev eth1 parent 1:1 classid 1:10 htb rate 6160000bit ceil 6160000bit prio 0
/sbin/tc qdisc add dev eth1 parent 1:10 handle 101: pfifo
/sbin/tc filter add dev eth1 parent 1: protocol ip prio 0 u32 match ip dst 192.168.1.0/24 flowid 1:10

this TC script works in ubuntu os(no use virtualbox), but it doesn't work in guest ubuntu os.

it only use VBoxManage bandwidthctl command to limit bandwidth on virtualbox environment?
TC command don't work on virtualbox environment? because guest get virtual nic physical network card not physical network card?

thanks