Hi, you can check the administration manual for solaris (online at oracles site), however if you want to reconfigure the network settings on a system and completely reset networking you could just run sys-unconfig as root which will then reboot and ask you for all the network settings, note this will remove all previous network configuration, known hosts, dns server ip's, hostname, interface ips etc but will let you easily re configure all of them step by step once the system reboots. Otherwise you need to modify network files within /etc such as /etc/hosts /etc/resolv.conf /etc/nsswitch.conf ....
Hope this helps.