:What do I do if the IP address of a Linux instance in the NIC configuration file is different from the IP address of the instance displayed in the ECS console?

Connect to the Linux instance.

For more information, see Use Workbench to connect to a Linux instance over SSH.

View the subnet mask.

Run the following command to view the routing information:

route -n

The sample command output shown in the following figure indicates the routing information of the Linux instance.

• The subnet mask (Genmask) is 255.255.255.0.

• The default gateway (Gateway) is 192.168.1.253.

Run the following command to modify or create the NIC configuration file:

sudo vi /etc/sysconfig/network-scripts/ifcfg-eth0

Use Static as the method for obtaining an IP address and configure the primary private IPv4 address and subnet mask of the NIC.

Sample code:

DEVICE=eth0
TYPE=Ethernet
#The method used to obtain an IP address, which is set to Static.
BOOTPROTO=static 

#The IPv4 address and subnet mask that require manual configuration.
IPADDR=<Replace the value of this parameter with the actual IPv4 address>
NETMASK=<Replace the value of this parameter with the actual subnet mask>

Example:

DEVICE=eth0
TYPE=Ethernet
#The method used to obtain an IP address, which is set to Static.
BOOTPROTO=static 

#The IPv4 address and subnet mask that require manual configuration.
IPADDR=192.168.1.201
NETMASK=255.255.255.0

Connect to the Linux instance.

For more information, see Use Workbench to connect to a Linux instance over SSH.

View the subnet mask.

Run the following command to view the routing information:

route -n

The sample command output shown in the following figure indicates the routing information of the Linux instance.

• The subnet mask (Genmask) is 255.255.255.0.

• The default gateway (Gateway) is 192.168.1.253.

Run the following command to disable the network configuration feature of cloud-init.

sudo vim /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg

Add the following configuration to the /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg configuration file:

network: {config: disabled}

Run the following command to open the /etc/netplan/50-cloud-init.yaml network configuration file and configure the NIC:

sudo vim /etc/netplan/50-cloud-init.yaml

Example:

network:
    version: 2
    ethernets:
        eth0: #The name of the NIC.
            dhcp4: false #By default, Dynamic Host Configuration Protocol (DHCP) is enabled to automatically assign IP addresses. If you set this parameter to false, you must manually configure IP addresses for the NIC.
            match:
                macaddress: 00:16:3e:16:43:xx #Replace the value of this parameter with the actual MAC address of the NIC.
            set-name: eth0
            addresses:
                    - 192.168.1.201/24 #Replace the value of this parameter with the actual primary private IPv4 address of the NIC.
            routes:
              - to: default
                via: 192.168.1.253 #Replace the value of this parameter with the actual default gateway address.

Connect to the Linux instance.

For more information, see Use Workbench to connect to a Linux instance over SSH.

View the subnet mask.

Run the following command to view the routing information:

route -n

The sample command output shown in the following figure indicates the routing information of the Linux instance.

• The subnet mask (Genmask) is 255.255.255.0.

• The default gateway (Gateway) is 192.168.1.253.

Run the following command to disable the network configuration feature of cloud-init.

sudo vim /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg

Add the following configuration to the /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg configuration file:

network: {config: disabled}

Run the following command to open the /etc/netplan/50-cloud-init.yaml network configuration file and configure the NIC:

sudo vim /etc/netplan/50-cloud-init.yaml

Example:

network:
    version: 2
    ethernets:
        eth0: #The name of the NIC.
            dhcp4: false #By default, DHCP is enabled to automatically assign IP addresses. If you set this parameter to false, you must manually configure IP addresses for the NIC.
            match:
                macaddress: 00:16:3e:16:43:xx #Replace the value of this parameter with the actual MAC address of the NIC.
            set-name: eth0
            addresses:
                    - 192.168.1.201/24 #Replace the value of this parameter with the actual primary private IPv4 address of the NIC.
            gateway4: 192.168.1.253 #Replace the value of this parameter with the actual default gateway address.