ALM-3245219843 Ethernet ARP IP Conflict Event

Description

ARP/4/ARP_IPCONFLICT_TRAP:OID [OID] ARP detects IP conflict. (IP address=[IPADDR], Local interface=[OCTET], Local MAC=[OCTET], Local vlan=[INTEGER], Local CE vlan=[INTEGER], Receive interface=[OCTET], Receive MAC=[OCTET], Receive vlan=[INTEGER], Receive CE vlan=[INTEGER], IP conflict type=[OCTET]).

An IP address conflict is detected by ARP.

Attribute

Alarm ID	OID	Alarm Severity	Alarm Type
3245219843	1.3.6.1.4.1.2011.5.25.123.2.6	Major	environmentalAlarm

Parameters

Name	Meaning
OID	Indicates the MIB object ID of the alarm.
IP address	IP address.
Local interface	Interface recorded in the ARP entry of the IP address.
Local MAC	Source MAC address recorded in the ARP entry of the IP address.
Local vlan	VLAN recorded in the ARP entry of the IP address.
Local CE vlan	CEVLAN recorded in the ARP entry of the IP address.
Receive interface	Inbound interface of the second ARP packet with the IP address.
Receive MAC	Source MAC address of the second ARP packet with the IP address.
Receive vlan	VLAN configured on the inbound interface of the second ARP packet with the IP address.
Receive CE vlan	CEVLAN configured on the inbound interface of the second ARP packet with the IP address.
IP conflict type	IP address conflict type.

Impact on the System

This alarm indicates that an IP address conflict occurred. If the IP address conflict is not eliminated timely, route flapping may occur and services may be interrupted.

Possible Causes

Cause 1: The source IP address in an ARP packet is the same as the IP address of the inbound interface that receives the ARP packet, but the source MAC address in the ARP packet is different than the MAC address of the inbound interface.
Cause 2: The source IP address in an ARP packet is the same as the IP address in an existing ARP entry, but the source MAC address is different than the MAC address in the ARP entry.
Cause 3: The source IP address in an ARP packet is 0.0.0.0 (probe ARP packet), the destination IP address is the same as the IP address of the inbound interface that receives the ARP packet, but the source MAC address in the ARP packet is different than the MAC address of the inbound interface.

Procedure

Identify the devices or users who use the same IP address.
- If the devices or users using the same IP address can be identified, modify the IP address of one device or user. Then, go to step 2.
- If the devices or users using the same IP address cannot be identified. Collect alarm information and configuration information, and then contact technical support personnel.
End.