The following describes how to install Zabbix agent 3.4.6 onto CentOS 6.9
1) Add Zabbix Repository
rpm -ivh http://repo.zabbix.com/zabbix/3.4/rhel/6/x86_64/zabbix-release-3.4-1.el6.noarch.rpm
2) Install Zabbix
yum install -y zabbix-agent
3) . Edit zabbix_agentd.conf
vi /etc/zabbix/zabbix_agentd.conf Server={Zabbix_Monitoring_server} Hostname={your_server_name}
4) Start Zabbix agent service
service zabbix-agent start
5) Add Zabbix Agent service to start up scripts
chkconfig zabbix-agent on