Why Does My ECS Fail to Obtain an IP Address?

The private IP address of the ECS fails to be obtained.

Locate the fault based on the following procedure.

Figure 1 Troubleshooting process

Check whether the DHCP function of the subnet is enabled (enabled by default).

Switch to the subnet details page. If DHCP is disabled, you must manually configure a static IP address for the ECS by referring to step 3.

Check whether the dhclient process exists:
ps -ef | grep dhclient
If the dhclient process does not exist, log in to the ECS and restart the ECS NIC or send a DHCP request.
- Linux:
  Run the dhclient ethx command. If dhclient commands are supported, run the ifdown ethx;ifup ethx command. In the command, ethx indicates the ECS NIC, for example, eth0 and eth1.
- Windows:
  Disconnect the network connection and connect it.
If the DHCP client does not send requests for a long time, for example, the fault occurs again after the NIC restarts, you can use the following method to configure the static IP address.
- Linux:
  1. Run the following command to open the /etc/sysconfig/network-scripts/ifcfg-eth0 file:
    vi /etc/sysconfig/network-scripts/ifcfg-eth0
  2. Modify the following configuration items in the /etc/sysconfig/network-scripts/ifcfg-eth0 file.
    BOOTPROTO=static
    
    IPADDR=192.168.1.100 #IP address
    
    NETMASK=255.255.255.0 #Subnet mask
    
    GATEWAY=192.168.1.1 #Gateway address
  3. Run the following command to restart the network service:
    service network restart
- Windows:
  On the Local Area Connection Status tab, click Properties. In the displayed area, select Internet Protocol Version 4 (TCP/IPv4) and click Properties. In the displayed area, enter the IP address, subnet mask, and the default gateway address.