Repo of Ubuntu scripts
Download the repo and change the permissions on all the shell scripts to allow it to be run. eg:
find Ubuntu_20.4/ -type f -iname "*.sh" -exec chmod u+x {} \;
find Ubuntu_20.4/ -type f -iname "run-dynamips" -exec chmod u+x {} \;
If an error about "/bin/bash^M: bad interpeter" replace suspicious characters using the following command:
sed -i -e 's/\r$//' <filename>