Thanks for reply
i try to achieve that if my internet from centos server is down then i have to take internet from another window pc on which net is connected .
as i told i have centos on which 2 nic card one etho connected to eth0 and bsnl isp line connected to eth1 via adsl modem.
set default gateway ip 10.10.1.169 (this is ip of window pc on which net is connected) in /etc/sysconfig/network file when i make /sbin/ifdown ppp0(ppp0 is bsnl link when bsnl link is working) then the server take default gateway 10.10.1.169 and net start in centos server but when
i remove telepone line from modem then default gateway ip 10.10.1.169 is not set ,if i manually set default gateway to 10.10.1.169 it set checked by route -n but after 3-4 min it is remove automatically pls suggest what is wrong and what i have to do