can not "ifup eth0" without dhcp server
 

Hi,

eth0 is configed as DHCP
how could I active it without a DHCP server present?
it may have any IP address if no DHCP server available,
just like what the DHCP client does in Windows

You have to configure the network with static IPs, or use local link IPs (see http://en.wikipedia.org/wiki/Link-local_address if you don't know what local link is).

What distribution? What version?

ok, i see,
thanks