dhcp anti-attack check udp-checksum

Function

The dhcp anti-attack check udp-checksum command enables the function of checking the UDP header checksum in a DHCP packet and discarding a DHCP packet with an incorrect checksum.

The undo dhcp anti-attack check udp-checksum command disables the function of checking the UDP header checksum in a DHCP packet.

By default, a device checks the UDP header checksum in a DHCP packet and discards a DHCP packet with an incorrect checksum.

Format

dhcp anti-attack check udp-checksum

undo dhcp anti-attack check udp-checksum

Parameters

None

Views

System view, VLAN view, Ethernet interface view, GE interface view, XGE interface view, 25GE interface view, MultiGE interface view, 40GE interface view, 100GE interface view, Eth-Trunk interface view, port group view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

The dhcp anti-attack check udp-checksum command applies to DHCP servers, DHCP relay agents, DHCP clients, and DHCP snooping-enabled devices. Devices from different vendors may use different DHCP implementation mechanisms. After checking the UDP header checksum in a received DHCP packet, a device may not allow the DHCP packet to pass through and discards the packet. As a result, DHCP becomes unavailable. To solve this problem, you can run the undo dhcp anti-attack check udp-checksum command to disable the function of checking the UDP header checksum in a DHCP packet, so that a DHCP packet with an incorrect UDP header checksum can be properly forwarded.

Prerequisites

DHCP has been enabled on the device using the dhcp enable command.

Example

# Disable the function of checking the UDP header checksum in a DHCP packet.

<HUAWEI> system-view
[HUAWEI] dhcp enable
[HUAWEI] undo dhcp anti-attack check udp-checksum