Some other blogs and sites also say that just input the IP address.
 
Therefore, I trusted that wiki and have no doubt.
 
Actually, the reason for using NAT is that I want to run the xorp (virtrual router software) on the domU and dom0.
 
When I used the virbr0 and xenbr0, the routing protocol runned by xorp did not find each other.
 
I tcpdumped all the interface on dom0, and thought that the bridge network did somethig strange.
 
Also, the vifX.0 dose not send or receive any of the packets and acts like a dummy.
 
So I configured the NAT mode and want the following situation.
 
----------------------------      --------------
|  eth0 ----- vif1.0 ---|------|---eth0   |
----------------------------      --------------
      dom0+xorp           dom1+xorp
 
As you mentioned, I inserted the static MAC address to the 'vif =[ ]' after the IP address.
 
However, it still does not show the POST screen.
 
PS) The xen on CentOS is a default package.