logfile=mail
virtual=127.0.0.1:10000
    real=127.0.0.2:80
    real=127.0.0.3:80
    service=http
virtual=127.0.0.1:20000
    real=127.0.0.2:80
    real=127.0.0.3:80
    service=https
virtual=127.0.0.1:30000
    real=127.0.0.2:80
    real=127.0.0.3:80
    checktype=connect
virtual=127.0.0.1:40000
    real=127.0.0.2:80
    real=127.0.0.3:80
    checktype=ping