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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