linux-troubleshooting an issue that is not recognized by the added NIC

Nic cannot be correctly identified and used after adding NIC
Error-Troubleshooting method
View the contents of the/etc/udev/rules.d/70-persistent-net.rules, which allows you to view the MAC address of the newly added NIC
Modify the MAC address of the/etc/sysconfig/network-scripts/ifcfg-eth0 network card to the correct MAC address
Use the System-config-network command to create a profile for the other NIC and set the IP address
#/etc/rc.d/init.d/network restart

NIC configuration file
/etc/sysconfig/network-scripts/ifcfg-eth0 's Content
Name of the Device=eth0 device
Physical address of the HWADDR=00:0C:29:AC:95:0C device
Nm_controlled=no whether to use NetworkManager for network interface management, default Yes
Onboot=yes whether the network interface is turned on when the system or network service is started, the default no
ipaddr=192.168.1.1 Defining IP Addresses
netmask=255.255.255.0 Defining a subnet mask
Type=ethernet Network type is Ethernet
How to get Bootproto=noneip
None do not use any startup protocol
DHCP uses the DHCP protocol as the startup protocol to obtain an IP address from a DHCP server
Static IP address used
Ipv6init=no whether the IPV6 configuration is supported
Userctl=no whether the network interface is allowed to be controlled by ordinary users
gateway=192.168.1.254 the address of the default gateway
DNS1=222.222.222.222 specifies the DNS server address that the host can look up
dns2=202.99.166.4
dns3=202.99.160.68

#ifconfig:
ifconfig [option] ethn [Ip/mask] [ACTION] action:up down
1. View IP address information: ifconfig [-A] [ETHN]
2. Configure IP Address information: ifconfig ethn ip/mask
3. Managing network Interfaces: Ifconfig ethn {Up|down}
Without directly modifying the configuration file, the execution results of the command are placed directly into the kernel, so the configuration parameters will take effect immediately, but will take effect after restarting the system or restarting the network service.

#system-config-network
To create a network card configuration file
The configuration file is modified directly, so it is permanently valid, but does not take effect immediately, only after rebooting the system or restarting the network service.

linux-troubleshooting an issue that is not recognized by the added NIC