man в лом читать?
-s, --source [!] address[/mask] Source specification. Address can be either a hostname, a network name, or a plain IP address. The mask can be either a network mask or a plain number, specifying the number of 1's at the left side of the network mask. Thus, a mask of 24 is equivalent to 255.255.255.0. A "!" argument before the address specification inverts the sense of the address. The flag --src is a convenient alias for this option.
если надо _исключить_ один адрес, можно писать "--src ! 192.168.1.237"