How to use a script to update the client configuration?

In our environment,there is no dns server,so wo used the /etc/hosts to resovle server and client,now We have added four servers,We need to add the resolve to all of the 300 clients,who can provide me the script?thank you  ！

the script must effect：

add the master and media server resolve to the client /etc/hosts

add the SERVER = MASTER   SERVER= MEDIA to the bp.conf

can not haveduplicate items