If a unix host is running properly but you only want to change hostname and/or IP address, please check the following check-list and make proper changes. This check-list applies to SDC only, other sites only for reference.
For Sun Solaris (you may change manually or try command "/usr/sbin/sys-unconfig"):

"/usr/sbin/showmount -a"
"exportfs -ua" or "unshareall"
/etc/hosts or /etc/inet/hosts
/etc/net/*/*host*
/etc/nodename
/etc/hostname.*
/etc/hosts.equiv
/etc/dumpadm.conf
/etc/rmtab
"cp /etc/nsswitch.files /etc/nsswitch.conf"
"rm -rf /var/nis", "rm /etc/.rootkey*"
reboot
/usr/lib/nis/nisclient -i -h sdc-master
/san/Solaris/Custom_Jumpstart/jumpstart/fin_sdc/rcs_and_misc_setup.fin -check_files
reboot

For RedHat Linux:

"/usr/sbin/showmount -a"
"exportfs -ua"
/etc/sysconfig/network-scripts/ifcfg-*
/etc/sysconfig/network
/etc/hosts
/etc/hosts.equiv
"cp /etc/nsswitch.files /etc/nsswitch.conf"
"rm -rf /var/nis", "rm /etc/.rootkey*"
reboot
/usr/lib/nis/nisinit -c -H sdc-master
/san/Solaris/Custom_Jumpstart/jumpstart/fin_sdc/rcs_and_misc_setup.fin -check_files
reboot