How to make permanent changes in resolv.conf

a) Set “PEERDNS=no”  and “PEERROUTES=no” in :

/etc/sysconfig/network-scripts/ifcfg-<whatever>

b) Set “NM_CONTROLLED=no” in:

/etc/sysconfig/network-scripts/ifcfg-<whatever>

c)  chattr +i /etc/resolv.conf

Note:

This options lock the entries in resolv.conf.