Help Center/ Huawei Qiankun CloudService/ More Documents/ Device Alarm Handling/ V200 LSW Alarms/ ALM-3276800475 The number of the discarded DHCP packets in which the CHADDR field is inconsistent with the source MAC address exceeds the threshold on the interface

Updated on 2024-01-25 GMT+08:00

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ALM-3276800475 The number of the discarded DHCP packets in which the CHADDR field is inconsistent with the source MAC address exceeds the threshold on the interface

Description

DHCP/1/REQMACTRAP:OID [OID] The number of the discarded DHCP packets in which the CHADDR field is inconsistent with the source MAC address exceeds the threshold on the interface. (IfIndex=[INTEGER], VlanIndex=[INTEGER], Interface=[OCTET], VlanID=[INTEGER], BdID=[INTEGER], DiscardedNumber=[INTEGER])

The number of discarded DHCP packets in which the CHADDR field and the source MAC address mismatched exceeded the threshold on the interface.

Attribute

Alarm ID	Alarm Severity	Alarm Type
3276800475	Warning	Equipment alarm

Parameters

Name	Meaning
OID	Indicates the MIB object ID of the alarm.
IfIndex	Indicates the interface index.
VlanIndex	Indicates the VLAN index.
Interface	Indicates the interface name.
VlanID	Indicates the VLAN ID.
BdID	Indicates the BD ID.
DiscardedNumber	Indicates the number of discarded packets.

Impact on the System

Invalid DHCP packets are discarded.

Possible Causes

The device considers DHCP packets in which the CHADDR field does not match the source MAC address as invalid DHCP packets.

Procedure

Configure port mirroring to obtain DHCP packets received by the interface. Check whether DHCP packets in which the CHADDR field does not match the source MAC address are attack packets.
- If a user connected to the interface sends a large number of DHCP packets in which the CHADDR field does not match the source MAC address, the user is an unauthorized user and the DHCP packets are attack packets. The device discards the attack packets. Check the attack source based on the source address.
- If users connected to the interface do not send a large number of DHCP packets in which the CHADDR field does not match the source MAC address, DHCP packets sent by the users are not attack packets. To ensure that the users pass the check, cancel the dhcp snooping check dhcp-chaddr enable command configuration on the interface.