good day. i jsut wanted to know what is the best script or the best way changing a lot of Ip's in all servers. Do you have any idea? im using awk to change IP,what if, you have lots of servers. You need to change it one by one? It will take time to change it manually.
Depends on the OS of the servers to be changed but generally speaking, you can write a script to log onto each server and update the files (have a big table mapping each IP to the new one and just do a search and replace of all of them on each server), then restart the network stack (if required).
Unless you are using DHCP, in which case it would be pretty easy, just do a big search and replace on your dhcptab file and refresh each server.
in linux,try to edit ifcfg-eth0 for linux servers, and /etc/rc.config.d/netconf in HP-UX, well i dont know in AIX. Maybe someone had an idea.
For automation, you can use awk and sed, that will change your IP or your subnet etc.. I have some machines too, that i made script to changed the IP.
all servers 10.131.3.xx i changed it to 10.121.3.xx but that servers were linux and hpux. i do manually running the scripts, but havent tried ssh 
maybe someone knows how to change ip not using smitty