Configuring a NIC (Red Hat, CentOS, Oracle Linux, and EulerOS)

This section uses CentOS 6.9 (x86_64) as an example to describe how to configure a NIC added to or deleted from a BMS.

Note

  • The configuration methods of Red Hat, Oracle Linux, EulerOS, and CentOS are similar.

  • If the network is disconnected after a NIC is added and the BMS is restarted, run the following command:

    ifup bond0.vlan

    vlan indicates the VLAN used by the NIC.

    If the network is still disconnected, add the NIC again.

Add a NIC

Use a key or password to log in to the BMS as user root. Run the following command:

blkid | grep config-2

If the command output is empty, use Method 2. If the command output shown in the following figure is displayed, use Method 1.

image1

  • Method 1

  1. Obtain information about the NIC to be added.

    Table 1 NIC information

    Parameter

    Description

    Example Value

    VLAN and MAC address

    Specifies the VLAN information and MAC address of the NIC. To obtain them, perform the following operations:

    1. In the BMS list, click the name of the target BMS to enter the BMS details page.

    2. Click the NICs tab, locate the row that contains the NIC to be added, and click image2 to expand details.

    3. Obtain the values of VLAN and MAC Address.

    2838

    fa:16:3e:1a:fd:5d

    Gateway

    Specifies the gateway address of the NIC. To obtain them, perform the following operations:

    1. On the NIC details page in 2, obtain the subnet information.

    2. On the BMS details page, click the link following VPC to switch to the VPC list.

    3. Click the name of the VPC to which the BMS belongs to go to the VPC details page.

    4. Click the Subnets tab and obtain the gateway address of the subnet in 1.

    192.168.1.1

  2. Use a key or password to log in to the BMS as user root.

  3. Run the following command to copy file /etc/sysconfig/network-scripts/ifcfg-bond0 to generate file /etc/sysconfig/network-scripts/ifcfg-bond0.vlan (replace vlan with the VLAN obtained in step 1, such as 2838):

    cp -p /etc/sysconfig/network-scripts/ifcfg-bond0 /etc/sysconfig/network-scripts/ifcfg-bond0.2838

  4. Run the following command to edit /etc/sysconfig/network-scripts/ifcfg-bond0.vlan and configure the network configuration file of the newly added NIC, such as ifcfg-bond0.2838:

    vim /etc/sysconfig/network-scripts/ifcfg-bond0.2838

    Edit the file as follows:

    MACADDR=fa:16:3e:1a:fd:5d
USERCTL=no
PERSISTENT_DHCLIENT=1
PHYSDEV=bond0
VLAN=yes
NM_CONTROLLED=no
BOOTPROTO=dhcp
DEVICE=bond0.2838
TYPE=Ethernet
ONBOOT=yes

    Descriptions of the parameters are as follows:

    • MACADDR: indicates the MAC address of the NIC to be added. For its value, see step 1.

    • DEVICE: Set it to bond0.vlan. vlan is the value obtained from 1, such as 2838.

    After the modification, press Esc and enter :wq to save the change and exit.

  5. Run the following command to start the added NIC:

    ifup bond0.vlan

    For example, to start bond0.2838, run the command shown in the following figure.

    image3

  6. Run the following command to check the status of the NIC device:

    image4

  7. Ping the gateway from the new network device to check whether the network connectivity is normal.

    Use the gateway address obtained from 1.

    image5

  • Method 2

  1. Obtain information about the NIC to be added.

    Table 2 NIC information

    Parameter

    Description

    Example Value

    MAC Address

    Specifies the MAC address of the NIC. To obtain them, perform the following operations:

    1. In the BMS list, click the name of the target BMS.

    2. Click the NICs tab, locate the row that contains the NIC to be added, and click image6 to expand details.

    3. Obtain the MAC address.

    fa:16:3e:4e:f7:ae

    Gateway

    Specifies the gateway address of the NIC. To obtain them, perform the following operations:

    1. On the NIC details page in 2, obtain the subnet information.

    2. On the BMS details page, click the link following VPC to switch to the VPC list.

    3. Click the name of the VPC to which the BMS belongs to go to the VPC details page.

    4. Click the Subnets tab and obtain the gateway address of the subnet.

    192.168.0.1

  2. Run the following command to query the name of the NIC whose MAC address is MACADDR:

    ifconfig -a | grep MACADDR -B 1

    MACADDR: indicates the MAC address of the NIC to be added. For its value, see step 1.

    image7

    As shown in the preceding figure, the NIC name is eth7.

  3. Run the following command to edit the /etc/sysconfig/network-scripts/ifcfg-eth7 file and configure the network configuration file of the new NIC:

    vim /etc/sysconfig/network-scripts/ifcfg-eth7

    Edit the file as follows:

    DEVICE=eth7
MACADDR=fa:16:3e:1a:fd:5d
BOOTPROTO=dhcp
ONBOOT=yes

    Where,

    • MACADDR: indicates the MAC address of the NIC to be added. For its value, see step 1.

    • Set DEVICE to the name of the new NIC. For its value, see step 2.

    After the modification, press Esc and enter :wq to save the change and exit.

  4. Run the following command to start the added NIC:

    ifup eth7

    For example, to start eth7, run the following command:

    image8

  5. Run the following command to check the status of the NIC device:

    image9

  6. Ping the gateway from the new network device to check whether the network connectivity is normal.

    Use the gateway address obtained from 1.

    image10

Delete a NIC

Use a key or password to log in to the BMS as user root. Run the following command:

blkid | grep config-2

If the command output is empty, use Method 2. If the command output shown in the following figure is displayed, use Method 1.

image11

  • Method 1

  1. Obtain the VLAN and MAC address of the NIC to be deleted.

  2. Use a key or password to log in to the BMS as user root.

  3. Locate the network device based on the VLAN information and run the following commands to stop and delete the device:

    [root@host-192-168-0-172 ~]# ip link | grep 2838
8: bond0.2838@bond0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 8888 qdisc noqueue state UP
[root@host-192-168-0-172 ~]# ifconfig bond0.2838 down
[root@host-192-168-0-172 ~]#
[root@host-192-168-0-172 ~]# ip link delete bond0.2838
[root@host-192-168-0-172 ~]#

  4. Run the following command to delete network configuration file /etc/sysconfig/network-scripts/ifcfg-bond0.vlan (replace vlan with the VLAN obtained from 1, such as 2838):

    rm /etc/sysconfig/network-scripts/ifcfg-bond0.2838

  • Method 2

  1. Obtain the VLAN and MAC address of the NIC to be deleted.

  2. Use a key or password to log in to the BMS as user root.

  3. Locate the network device based on the VLAN information and run the following commands to stop and delete the device:

    [root@bms-197-31 ~]# ip link | grep fa:16:3e:4e:f7:ae -B 1
9: eth7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether fa:16:3e:4e:f7:ae brd ff:ff:ff:ff:ff:ff
[root@bms-197-31 ~]# ifconfig eth7 down
[52574.065410] hinic 0000:89:00.0 eth7: [NIC]Netdev is down

  4. Run the following command to delete network configuration file /etc/sysconfig/network-scripts/ifcfg-eth7:

    rm /etc/sysconfig/network-scripts/ifcfg-eth7

last updated: 2025-02-13 16:23 UTC - commit: 9f2c6335cb474a1f2d68189ad120b0cea918aac6