DHCP protocol troubleshooting: IP cannot be obtained

DHCP protocol troubleshooting problem. This time, we mainly aim at the failure of clients to obtain IP addresses through the DHCP server. In this regard, what problems should we pay attention to, as well as its analysis and specific handling steps? Next we will look at it in detail.

DHCP protocol troubleshooting ◆ Network Environment

As shown in. In this networking environment, you can configure a global address pool on the server and find that the client cannot obtain the IP address.

Figure conflict between IP addresses obtained through DHCP

DHCP protocol troubleshooting ◆ Fault Analysis

Possible causes of faults include:

● DHCP service not started

● The Network and interface GigabitEthernet1/0/0 of the address pool are not in the same Network segment

● Physical line problems

DHCP protocol troubleshooting ◆ operation steps

1. Execute the display dhcp server tree all command and check that the global address pool is configured. The Network is 1.1.1.0, And the subnet mask is 255.255.0.0.

2. Run interface gigabitethernet1/0/0 in the System View To Go To The interface view of GigabitEthernet1/0/0.

3. Run the display this command to check that the IP address of GigabitEthernet1/0/0 is 2.2.2.2. the IP address of the interface and the Network of the address pool are not in the same Network segment.

4. In the interface view, run ip address 1.1.1.1 16 to change the ip address of GigabitEthernet1/0/0 to the ip address 1.1.0.0 segment. You can also modify the Network of the address pool so that it is in the same Network segment as the interface address ).

DHCP protocol troubleshooting ◆ task example

After completing the preceding operations, the client applies for an IP address and resolves the fault.

DHCP protocol troubleshooting ◆ case summary

In the Network environment where the client and server are directly connected, when an IP address is allocated using the global address pool, the IP addresses of the Network and interface GigabitEthernet1/0/0 must be configured in the same Network segment.