摘要： [root@localhost ~]# cat /etc/hosts.allow ## hosts.allow This file contains access rules which are used to# allow or deny connections to network services that# either use the tcp_wrappers library or that have been# started through a tcp_wrappers-enabled xinetd.## See 'man 5 hosts_options' and 阅读全文

摘要： 系统默认的shell在，/etc/default/useradd中，添加用户的时候如果不指定shell，默认的shell就是该文件下制定的文件 阅读全文

摘要： vi /etc/sysconfig/iptables把icmp那行的ACCEPT改成DROP，重启iptables 阅读全文