Error-php using SSH2 times wrong, Invalid MAC

Error PHPSSH2

Warning:ssh2_connect (): Error Starting up SSH connection ( -4): Invalid MAC received in/var/www/html/ssh.php on line 10
Warning:ssh2_connect (): Unable to connect to 192.168.30.72 in/var/www/html/ssh.php on line 10
Warning:ssh2_auth_password () expects parameter 1 to BES resource, boolean given in/var/www/html/ssh.php on line cannot Log in

Report these mistakes.

The code is as follows
$con = Ssh2_connect ($host, ' 22 ');
if (Ssh2_auth_password ($con, $user, $passwd)) {
$stream = Ssh2_exec ($con, "LS");
Print $stream;
} else print ' cannot log in ';

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