| Message Code | ASA-4-405001 |
| Severity | Warning |
| Description | Received ARP {request | response} collision from IP_address/MAC_address on interface interface_name to IP_address/MAC_address on interface interface_name |
| Explanation | The adaptive security appliance received an ARP packet, and the MAC address in the packet differs from the ARP cache entry. |
| User Action | This traffic might be legitimate, or it might indicate that an ARP poisoning attack is in progress. Check the source MAC address to determine where the packets are coming from and check to see if it belongs to a valid host. |
| Reference Links |
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