thanks very much !!!
well ,I have two NIC: private network connect (connet to LAN) and public network connect (connet to ADSL Modem).
private network connect :
IPADDR---192.168.0.1
Subnetmask--255.255.255.0
no Gateway
public network connect:
have a dynamic IPADDR
I have two OS on my disk. Linux & Winxp. Under winxp,everything is OK,but not under linux (drop after while interval).
so,I'm very confusion.The same way (both use dynamic IPADDR),but,the different result