You should put it into command line in windows.
mysqladmin -u [username] -p flush-hosts
**** [MySQL password]
or
mysqladmin flush-hosts -u [username] -p
**** [MySQL password]
For network login use the following command:
mysqladmin -h <RDS ENDPOINT URL> -P <PORT> -u <USER> -p flush-hosts
mysqladmin -h [YOUR RDS END POINT URL] -P 3306 -u [DB USER] -p flush-hosts
you can permanently solution your problem by editing my.ini file[Mysql configuration file] change variables max_connections = 10000;
or
login into MySQL using command line -
mysql -u [username] -p
**** [MySQL password]
put the below command into MySQL window
SET GLOBAL max_connect_errors=10000;
set global max_connections = 200;
check veritable using command-
show variables like "max_connections";
show variables like "max_connect_errors";