Centos7 network configuration comparison with previous versions

Centos7 network configuration comparison with previous versions

Because the network configuration of Centos7 is significantly different from that of previous versions, we will discuss it separately.

Centos 7 has the automatic detection function for Nic devices:

(1) Nic naming mechanism
Systemd naming for network devices:
(A) if the index information provided by the Firmware or BIOS integration device on the master board is available and predictable, name the index, for example, eno1;
(B) if the index information provided by Firmware or BIOS for the PCI-E expansion slot is available and predictable, name the index, such as ens1;
(C) if the physical location information of the hardware interface is available, name it, for example, enp2s0;
(D) If you start the service explicitly, you can also name it based on the MAC address, enx2387a1dc56;
(E) If none of the above are available, the traditional naming mechanism is used;

Some of the above naming mechanisms require the participation of the biosdevname program;

(2) name composition format
En: ethernet
Wl: wlan
Ww: wwan wireless WAN

Name type:
O <index>: The device index Number of the Integrated Device;
S <slot>: Index Number of the expansion slot;
X <MAC>: MAC address-based naming;
P <bus> s <slot>: enp2s1

Nic device naming process:
Step 1:
Udev, auxiliary tool/lib/udev/rename_device,/usr/lib/udev/rules. d/60-net.rules
Read configuration files
Step 2:
Biosdevname will be based on/usr/lib/udev/rules. d/71-biosdevname.rules

Step 3:
Check the network interface device 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) edit 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) restart the system

Address Configuration tool: nmcli:

Display Network Information: nmcli device show [dev eth0]

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

How to modify attributes such as IP addresses:
# 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

Host Name Configuration tool: hostnamectl
Status
Set-hostname