ARP/4/ARP_DUPLICATE_IPADDR

Message

ARP/4/ARP_DUPLICATE_IPADDR: Received an ARP packet with a duplicate IP address from the interface. (InterfaceName=[InterfaceName], IpAddress=[IpAddress], MacAddress=[MacAddress], PE-VLAN=[PeVLAN], CE-VLAN=[CeVLAN])

Description

An interface received an ARP packets carrying an IP address the same as an existing one.

Parameters

Parameter Name	Parameter Meaning
InterfaceName	Name of an interface
IpAddress	IP address that is conflicted with the existing one
MacAddress	MAC address
PeVLAN	Outer VLAN
CeVLAN	Inner VLAN

Possible Causes

Cause 1: Another device on the network is configured with the same IP address as the local device. Cause 2: There are ARP spoofing attacks with bogus source IP addresses.

Procedure

Cause 1: Another device on the network is configured with the same IP address as the local device.

Check the devices with the same IP address on the network according to the conflicting VLAN, interface, and IP address in the log. Modify the interface IP address according to the address planning to remove the address conflict.

Cause 2: There are ARP spoofing attacks with bogus source IP addresses.

Find the attack source according to the conflicting VLAN, interface, and IP address in the log, and configure the device to prevents ARP spoofing attacks. In addition, you are advised to remove virus from the PC or server in the attacked network.