Install virtual network card in Ubuntu 8.10

1 install uml-utilities

sudo apt-get install uml-utilities

2 build a new virtual Network Card

tunctl -t tap0 -u edwin

3 delete this virtual network card

tunctl -d tap0

4 config tap0

ifconfig tap0 192.168.6.1 netmask 255.255.255.0

5 add network card when system startup

sudo gedit /etc/network/interfaces

add the following content

auto tap0
iface tap0 inet manual
     up ifconfig $IFACE 192.168.6.1 up
     down ifconfig $IFACE down
     tunctl_user edwin