anchor.diff:      };
   
       networking.nat.internalIPs = mkOption {
  -      example = "192.168.1.0/24";
  +      example = [ "192.168.1.0/24" ] ;
         description =
           ''
  -          The IP address range for which to perform NAT.  Packets
  -          coming from these addresses and destined for the external
  +          The IP address ranges for which to perform NAT.  Packets
  +          coming from these networks and destined for the external
             interface will be rewritten.
           '';
       };
  
positive.code:           ''
              iptables -t nat -F POSTROUTING
              iptables -t nat -X
  
              iptables -t nat -A POSTROUTING \
                -s ${cfg.internalIPs} -o ${cfg.externalInterface} \
                ${if cfg.externalIP == ""
                  then "-j MASQUERADE"
                  else "-j SNAT --to-source ${cfg.externalIP}"}
  
              echo 1 > /proc/sys/net/ipv4/ip_forward
            '';
  
  
negative.code:             iptables -t nat -F POSTROUTING
            '';
        };
    };
  }
  