4.2. Keepalived Direct Routing Configuration

Direct Routing configuration of Keepalived is similar in configuration with NAT. In the following example, Keepalived is configured to provide load balancing for a group of real servers running HTTP on port 80. To configure Direct Routing, change the lb_kind parameter to DR. Other configuration options are discussed in Section 4.1, “A Basic Keepalived configuration”.
The following example shows the keepalived.conf file for the active server in a Keepalived configuration that uses direct routing. 
global_defs {
   notification_email {
     admin@example.com
   }
   notification_email_from noreply_admin@example.com
   smtp_server 127.0.0.1
   smtp_connect_timeout 60
}

vrrp_instance RH_1 {
    state MASTER 
    interface eth0
    virtual_router_id 50
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass passw123
    }
    virtual_ipaddress {
        172.31.0.1
    }
}

virtual_server 172.31.0.1 80
    delay_loop 10
    lb_algo rr
    lb_kind DR
    persistence_timeout 9600
    protocol TCP

    real_server 192.168.0.1 80 {
        weight 1
        TCP_CHECK {
          connect_timeout 10
          connect_port    80
        }
    }
    real_server 192.168.0.2 80 {
        weight 1
        TCP_CHECK {
          connect_timeout 10
          connect_port    80
        }
    }
    real_server 192.168.0.3 80 {
        weight 1
        TCP_CHECK {
          connect_timeout 10
          connect_port    80
        }
    }
}
The following example shows the keepalived.conf file for the backup server in a Keepalived configuration that uses direct routing. Note that the state and priority values differ from the keepalived.conf file in the active server. 
global_defs {
   notification_email {
     admin@example.com
   }
   notification_email_from noreply_admin@example.com
   smtp_server 127.0.0.1
   smtp_connect_timeout 60
}

vrrp_instance RH_1 {
    state BACKUP
    interface eth0
    virtual_router_id 50
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass passw123
    }
    virtual_ipaddress {
        172.31.0.1
    }
}

virtual_server 172.31.0.1 80
    delay_loop 10
    lb_algo rr
    lb_kind DR
    persistence_timeout 9600
    protocol TCP

    real_server 192.168.0.1 80 {
        weight 1
        TCP_CHECK {
          connect_timeout 10
          connect_port    80
        }
    }
    real_server 192.168.0.2 80 {
        weight 1
        TCP_CHECK {
          connect_timeout 10
          connect_port    80
        }
    }
    real_server 192.168.0.3 80 {
        weight 1
        TCP_CHECK {
          connect_timeout 10
          connect_port    80
        }
    }
}