checkzero (RIP)

Function

The checkzero command enables the device to check the zero fields in RIP-1 packets.

The undo checkzero command disables the device from checking the zero fields in RIP-1 packets.

By default, the device checks the zero fields in RIP-1 packets.

Format

checkzero

undo checkzero

Parameters

None

Views

RIP view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

In a RIP-1 packet, the values of some fields must be zero. These fields are zero fields. After zero field check is enabled, the device checks the zero fields in the RIP-1 packets and discards the packets in which the zero field values are not 0.

The checkzero command is valid only for RIP-1 packets.

Run the undo checkzero command to reduce CPU usage if there is no zero field to check (all neighbors are trusted).

Configuration Impact

By default, devices reject all RIP-1 packets in which the zero fields are not 0.

RIP-1 implementations vary with device manufacturers. If the third-party peer device allows zero fields in RIP-1 packets to carry non-zero values, run the undo checkzero command on the local device. The undo checkzero command causes potential security risks to network, so it is not recommended.

Example

# Enable the device to check zero fields in RIP-1 packets.

<HUAWEI> system-view
[HUAWEI] rip 100
[HUAWEI-rip-100] checkzero