Be careful with the setup command since it recreates filers (exports hosts, hosts.equiv, resolv.conf, nsswitch.conf), but it does create .bak backup files prior to recreating them...but I don't like re-running setup since it takes edits to put things back if not a new install.
It is usually easier to just change /etc/hosts for the new IP if you are comfortable editing the file, then either reboot or rerun ifconfig to change the IP. Filerview used to have some "interesting" behavior with network changes (rc/hosts edits where the interface won't come up on reboot) but those are likely fixed now. System Manager is a solid interface and I'd trust it more than filerview.