1. The command to clear the ARP table is incorrect: Please make sure to use the correct command to clear the ARP table. For example, on the H3C switch, you can use the following command to clear the ARP table: resetarp.
2. There are static ARP entries in the ARP table: if there are static ARP entries in the ARP table, these entries cannot be deleted by cleaning the ARP table. You need to manually delete these static ARP entries.
3. There are abnormal entries in the ARP table: there are abnormal entries in the ARP table, such as duplicate IP addresses or MAC addresses, which will lead to invalid ARP table cleaning. These abnormal entries need to be deleted manually.