could not bind to address 0.0.0.0:443 啥意思？

Mr.zy

[root@Mr root]# /usr/sbin/apachectl start
httpd (pid 2331) already running

httpd 起动ok,但 www 不能用，出现这样的错误

[root@Mr root]# httpd
(9!!!!!!!!!!!!: make_sock: could not bind to address 0.0.0.0:443
no listening sockets available, shutting down

怎回事？  could not bind to address 0.0.0.0:443 啥意思？

  谢谢！