To install the CORE network emulator in recently released Linux distributions, including Ubuntu 16.04 and later, I recommend that you install it from the CORE Github source code repository.
The Debian and Ubuntu maintainers will remove CORE packages from their repositories in the near future so we cannot install CORE using a package manager, anymore. We also cannot use the packages available on the CORE web site until a new version of CORE is released, because newer Linux distributions may break some of the functionality in the version of CORE packages available there. For example, CORE fails to start Quagga routing daemons in newer Linux distributions. The issue is fixed in the latest version of the CORE source code available on Github.
The CORE source code is in two places: on the CORE web site, and on Github. It’s not completely clear which source code repository we should use to build CORE from. I asked the CORE team about this and it seems that both are valid, but are not kept 100% in sync with each other. Since a recent fix I needed was on the CORE Github repository, but not in the CORE web site nightly snapshots source code folder, I will use the CORE GitHub repository.
In this post, I provide a detailed procedure to install CORE from the source code on Github, and to set up your system to run network experiments using the CORE network emulator.