A: It is not recommended. These sources often contain bundled malware or are modified versions that can be unstable. Using cracked license generators is illegal and poses a significant security threat to your system.
A: No, OPNET Modeler was a commercial product. However, its successor "IT Guru Academic Edition" was free for academic use. After the Riverbed acquisition, the product line has been discontinued, and no official free version is publicly available for download. download opnet modeler 16.1