20150312Wrapper, Firewall

1,TCP Wrapper is a tool for access control . Effective in real time. /etc/hosts.allow,/etc/hosts.deny

Eg: allow only 172.16.0.1 logon Telnet:vim/etc/hosts.deny write: In.telnetd:ALL EXCEPT 172.16.0.1

Not all services can be implemented with TCP wrapper, only the daemon that are connected to the LibWrap module.

LDD $ (which httpd) |grep wrap

2. One of the biggest advantages of FIREWALLD is that any change takes effect in real time because he modifies only the changed parts, while Iptables is recreating all the rule, thus breaking the current connection.

systemctl The Service systemctl command to serve and Chkconfig commands combined.

Although the FIREWALLD is in effect immediately, if a restart is required, you can restart the service, or you can reload the service

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http://blog.csdn.net/julius819/article/details/7665679

 firewall-cmd--get-service View service, Firewall-cmd--query-service=http judge whether the service is open, --permanent Permanent entry

3. Port forwarding

20150312Wrapper, Firewall