These days i need to change the network card and the “service network restart” show that mac address is another than expected, so i go terminal and type find -iname network , find one in /etc/rc.d/init.d/network, so i type vi network and saw the “path of rocks”, that is /etc/sysconfig, i gone to it and type ls, so i find the dir called /networking, more one ls and saw devices, at last vi ifcfg-eth1 (my trouble! ) and change the mac address . This troubles was gone.

The other trouble i change the ip for one that given to me, so i need change in /etc/sysconfig the file iptables (all the including the old address of my eth0) including the SNAT line, change the new ip with ifconfig and ok, i hope thats work.

calculating the broadcast address for one ip give with netmask

ip 201.12.57.102 change to binary 11001001 00001100 00111001 01100110

add netmask (255.255.255.224) 11111111 11111111 11111111 11110000

AND logic give network 11001001 00001100 00111001 01100000 thats give us the network address 201.12.57.96

então pela lógica o end broadcast os ultimos binarios ficariam 01111111 ou seja .127

resolvido