An AP fails to obtain an IP address through DHCP

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Perform the following steps to locate the fault:
1. Check whether the AP is configured to obtain an IP address through DHCP.
2. Check whether the Layer 2 link between the AP and DHCP server is working properly.
3. Run the display ip pool name ip-pool-name used command on the DHCP server to check whether the AP has obtained an IP address.

Other related questions:
An AP fails to obtain an IP address
If the management address pool for APs is created on an AC, run the display ip pool name ip-pool-name used command on the AC. If the command output displays an AP's MAC address and a corresponding IP address, the AP has obtained an IP address. You can also run the following command to check whether an AP has obtained an IP address: - For V200R005 or earlier version: display ap-run-info id ap-id - For V200R006 or a later version: display ap all

What measures should be taken when an AP fails to obtain an IP address using DHCP
Perform the following steps to locate the fault: 1. Check whether the AP is configured to obtain an IP address using DHCP. 2. Check whether the Layer 2 link between the AP and DHCP server is working properly. 3. Run the display ip pool name ip-pool-name used command on the DHCP server to check whether the AP has obtained an IP address.

DHCP clients fail to obtain IP addresses from the DHCP server on the AR
The causes that DHCP clients fail to obtain IP addresses from the DHCP server are as follows: - The configuration is incorrect. - There is no allocable IP address in the DHCP address pool. - STP is enabled on upper-level access devices of some diskless workstations. For details on troubleshooting and solutions, see AR150&AR160&AR200&AR510&AR1200&AR2200&AR3200 FAQ.
About the AR ClientExceptions occurs when the IP address is obtained. For details, see the Revelations of Troublesolving on the right page.

Why does a user on an AR slowly obtain an IP address
The cause is that the interface is enabled with STP. By default, all interfaces of an AR are configured with STP. When the interface changes from Down to Up, STP convergence is performed (the process takes about 30s). During STP convergence, an interface on an AR directly discards received packets. That is, DHCP Request messages are all discarded during the STP convergence period. IP addresses are obtained slowly in this case. Use either of the following methods to solve this problem: - Run the stp edged-port enable command on the AR interface connected to a user terminal to configure the interface as an edge interface. If the AR is configured with the stp bpdu-protection command, the edge interface of the AR becomes Down when there are malicious attacks of BPDUs. To enable the edge interface to automatically go Up, run the error-down auto-recovery cause bpdu-protection interval interval-value command. - If there is no physical loop, run the stp disable command on the AR in the system view or the AR interface connected to a user terminal.

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