Install iPerf on CentOS

yum -y install yum-plugin-priorities
sed -i -e "s/\]$/\]\npriority=1/g" /etc/yum.repos.d/CentOS-Base.repo
yum -y install http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
sed -i -e "s/\]$/\]\npriority=5/g" /etc/yum.repos.d/epel.repo
yum --enablerepo=epel -y install iperf3   # install from EPEL