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As of February 2016, NMIS is distributed in a self-extracting download format that simplifies the installation process quite a bit. More information on installer options can be found HERE: The Opmantek Installer
You can download NMIS from the Opmantek website at https://opmantek.com/network-tools-download/; the distribution file is called nmis<version>.run, and your browser will likely prompt you regarding what to do with this '.run' file; you should tell it to Save the file, ideally in /tmp.
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