How to Set IP addresses in Linux

Static Method
Note: All operations use the root user.
Modify IP Address:
Edit file/etc/sysconfig/network-scripts/ifcfg-eth0
Device = eth0 // device name, do not modify
Bootproto = static // do not modify
Broadcast = 10.10.22.255 // broadcast address, which is generally the last IP address of the network segment
Ipaddr = 10.10.22.145 // ip address
Netmask = 255.255.255.0 // Subnet Mask
Network = 10.10.22.0 // CIDR block address
Onboot = Yes // do not modify
Type = Ethernet // do not modify
Note: The ifcfg-eth0 is the first Nic, The ifcfg-eth1 is the second Nic, and so on

Add IP Address:
You can recompile a file named/etc/sysconfig/network-scripts/ifcfg-eth0: 0
You can also add it directly in/etc/sysconfig/network-scripts/ifcfg-eth0 (but the device eth0 must have)
Device = eth0: 0 // device name, do not modify
Bootproto = static // do not modify
Broadcast = 10.10.33.255 // broadcast address, which is generally the last IP address of the network segment
Ipaddr = 10.10.33.145 // ip address
Netmask = 255.255.255.0 // Subnet Mask
Network = 10.10.33.0 // network segment address
Onboot = Yes // do not modify
Type = Ethernet // do not modify

And so on. If you add another IP address, add the following Configuration:
Device = eth0: 1 // device name, do not modify
Bootproto = static // do not modify
Broadcast = 10.10.44.255 // broadcast address, which is generally the last IP address of the network segment
Ipaddr = 10.10.44.145 // ip address
Netmask = 255.255.255.0 // Subnet Mask
Network = 10.10.44.0 // CIDR block address
Onboot = Yes // do not modify
Type = Ethernet // do not modify

Similarly, if you are on the second Nic, you need to add:
Device = eth1: 0 // device name, do not modify
Bootproto = static // do not modify
Broadcast = 10.10.33.255 // broadcast address, which is generally the last IP address of the network segment
Ipaddr = 10.10.33.145 // ip address
Netmask = 255.255.255.0 // Subnet Mask
Network = 10.10.33.0 // network segment address
Onboot = Yes // do not modify
Type = Ethernet // do not modify

Add the Default Gateway:
Note that only one machine can have one default gateway; otherwise, a specific routing method should be provided.
Add one to the related device configuration. For example, in the above configuration, add a default gateway to the first IP address of the first NIC:
Device = eth0
Bootproto = static
Broadcast = 10.10.22.255
Ipaddr = 10.10.22.145
Netmask = 255.255.255.0
Network = 10.10.22.0
Onboot = Yes
Type = Ethernet
Gateway = 10.10.22.3

After the modification, You need to restart the machine or network to make the modification take effect.
The method to restart the machine is: reboot
The method to restart the network is: Service Network restart

The preceding method adds IP addresses statically, that is, it is still effective after the machine is restarted.

Dynamic Method
Note: All operations use the root user.
Modify IP Address:
Ifconfig eth0 10.10.22.145
Change the IP address of the first ENI to 10.10.22.145.

Add IP Address:
Ifconfig eth0 add 10.10.33.145 // Add an IP address
Ifconfig eth0: 0 broadcast 10.10.33.255 // modify the broadcast address of the added IP Address

Add another IP Address:
Ifconfig eth0: 0 add 10.10.44.145
Ifconfig eth0: 0: 1 Broadcast 10.10.44.255 // modify the broadcast address of the added IP Address
Do not perform the following operations:
Ifconfig eth0 add 10.10.44.145
In this way, the added ip10.33.145 is changed to 10.10.44.145.

Add another IP Address:
Ifconfig eth0: 0: 1 add 10.10.55.145
Ifconfig eth0: 0: 1: 1 Broadcast 10.10.55.255 // modify the broadcast address of the added IP Address

And so on
After adding the above, it takes effect immediately, but the machine becomes invalid after it is restarted.