[CentOS] resolv.conf rewritten every reboot. How to figure out who and why?

> You guessed right. But the question remains, what software is writing the file?

/etc/init.d/network calls /etc/sysconfig/network-scripts/ifup which
calls /sbin/dhclient which calls /sbin/dhclient-script which
overwrites your resolv.conf with the info it gets from the DHCP server
on the network.

M