Linux System Management-(-CENTOS7) network configuration

Because the network configuration of Centos7 has a large gap with previous versions, it is discussed separately.

Centos 7 has automatic detection capability for network card devices:

      (1) network card naming mechanism
            systemd naming network devices:
                 (a) if the index information provided by the firmware or BIOS integrated devices on the main board is available, And can be predicted based on this index name, such as Eno1;
                 (b) If the index information provided by the firmware or BIOS for the PCI-E expansion slot is available and predictable, it is named according to this index, such as ens1;
                 (c) If the physical location information of the hardware interface is available, it is named according to this information, For example Enp2s0;
                 (d) If the user explicitly starts, it can also be named according to the MAC address , ENX2387A1DC56;
                 (E) When none of the above is available, use the traditional naming mechanism;

                 The above naming mechanism, some need to biosdevname program participation;

(2) Name composition format
En:ethernet Ethernet
Wl:wlan Wireless LAN
Ww:wwan Wireless Wan

Name Type:
O<INDEX>: Device index number of the integrated device;
S<slot>: index number of the expansion slot;
X<mac>: Name based on MAC address;
P<bus>s<slot>: enp2s1

        naming procedures for network card devices:
              First step:
                udev, auxiliary tools/ Lib/udev/rename_device,/usr/lib/udev/rules.d/60-net.rules
                 Read configuration file
             Step Two:
                biosdevname will be based on/usr/lib/udev/ Rules.d/71-biosdevname.rules

             Step three:
                 by detecting network interface devices, according to/usr/lib/udev/rules.d/75- Net-description
                     Id_net_name_onboard, Id_net_name_slot, Id_net_name_path

Return to the traditional naming method:
(1) Editing the/etc/default/grub configuration file
grub_cmdline_linux= "Net.ifnames=0 rhgb quiet"

(2) generate its configuration file for Grub2
Grub2-mkconfig-o/etc/grub2.cfg

(3) Rebooting the system

Address Configuration tool: Nmcli:

Display Network information: NMCLI device show [Dev Eth0]

Nmcli Con {show | up | | | add | modify | edit | delete | reload | load}

How to modify properties such as IP address:
#nmcli Connection Modify Interface name [+|-]setting.property value
Setting.property:
Ipv4.addresses
Ipv4.gateway
Ipv4.dns1
Ipv4.method
Manual

Network Interface Configuration TUI tool: Nmtui
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Host name Configuration tool: Hostnamectl
Status
Set-hostname

Linux System Management-(-CENTOS7) network configuration