7.3.7 Setting Up an Install Server
You cannot boot Solaris 2.X through a router. The install server must be on the same subnet as the client. You don't, however, need to have a complete install server on each subnet. You can have a pared down boot server on the subnet with the kernel architecture required for those subnet clients, and a full install server on another subnet.
After adding the machine as a client of the install server halt and boot the client from the network:
ok boot net
After the client completes the boot process the suninstall program is invoked automatically.