CentOS commands for viewing IP addresses, modifying IP addresses on ports, and activating ports

CentOS commands for viewing IP addresses, modifying IP addresses on ports, and activating ports

You know, you get used to ipconfig in windows, and it is a lot of trouble to view IP addresses in CentOS;

The information collected today focuses on IP port problems:

1. View IP
   Ifconfig eth0 → view the IP address, but the output information is more
   Ifconfig | grep 'bcast' → the output information should be much clearer.
2. Modify IP address and take effect
   Edit/etc/sysconfig/network-scripts/ifcfg-eth0 and follow the settings below
   DEVICE = eth0
   BOOTPROTO = static
   HWADDR =
   ONBOOT = yes
   TYPE = Ethernet
   IPADDR = <your IP address>
   NETMASK = 255.255.255.0
   The MAC address can be viewed using the ifconfig eth0 command.
   After setting, restart the network service:Service network restart
3. After the CentOS system is installed, only port 22 is enabled by default. to open other ports, open the required ports.

Vi/etc/sysconfig/iptables

Then add the Java code to the CentOS system.
-A RH-Firewall-1-INPUT-m state -- state NEW-m tcp-p tcp -- dport 3001-j ACCEPT
-A RH-Firewall-1-INPUT-m state -- state NEW-m tcp-p tcp -- dport 3001-j ACCEPT

Finally, the CentOS system needs to restart the service Java code.
/Sbin/service iptables restart
/Sbin/service iptables restart

Check whether Java code is enabled on the port

/Sbin/iptables-L-n