Hi,
If u want to use the new settings , you can
a) inject the new default route to the existing routing table
route delete default <old-gateway>
route add default <new-gateway>
Note: Don't delete the old gateway info if you are logged in over the network from a remote network .
b) Restart the network services .
Pre-Solaris 10
/etc/init.d/inetinit stop
/etc/init.d/inetinit start
/etc/init.d/inetsvc stop
/etc/init.d/inetsvc start
Solaris 10 <
svcadm restart network ( i am not too sure of this )
Hope this helps
Rgds
PK