[Blind-sysadmins] Accessible network simulator

Hello. Due to my study classes, I faced an interesting problem, which is inaccessibility of Cisco Packet Tracer, and lack of any accessible alternative as far as I investigated it. But, possibly somebody can suggest something about it: Is any way of enabling accessibility in Packet tracer, and constructing networks there? Maybe some other software is available to accomplish simulation of basic networks conssisting of few routers, some computers, switches and DHCP server? Probably something script-driven and working in console mode, or dumping textual results into file? I found a NS-3 simulator, but at the moment, didn't go deep in it, because I'm not sure if it'll work for me. Greetings, Greg.