purge-originator-identification enable

Function

The purge-originator-identification enable command enables whether IS-IS adds the purge originator identification (POI) TLV and hostname TLV to Purge LSPs to be sent.

The undo purge-originator-identification command restores the default configuration.

By default, Purge packets do not carry POI TLV or hostname TLV.

Format

purge-originator-identification enable

purge-originator-identification enable always

undo purge-originator-identification enable

Parameters

Parameter	Description	Value
always	Enables IS-IS to always add the POI TLV and dynamic hostname TLV to Purge LSPs to be sent.	-

Parameter

Description

Value

always

Enables IS-IS to always add the POI TLV and dynamic hostname TLV to Purge LSPs to be sent.

Views

IS-IS view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
isis	write

Usage Guidelines

Usage Scenario

When Remaining Lifetime of an LSP is 0, the LSP is invalid, and this invalid packet is a Purge packet. In most cases, a Purge packet does not carry any information about the router that generated the Purge packet. Without such information, troubleshooting is difficult if a network problem occurs.

To address this issue, you can run the

purge-originator-identification enable command to configure IS-IS to add POI TLV to Purge packets. If a dynamic hostname has been configured for the local device, the hostname TLV is also added to the Purge packets, which facilitates troubleshooting.

If the purge-originator-identification enable command is run and the send-only parameter is specified when configuring authentication, generated Purge LSPs do not carry the POI TLV or hostname TLV.
If the purge-originator-identification enable command is run and HMAC-MD5 authentication is configured, generated Purge LSPs do not carry the POI TLV or hostname TLV. If the purge-originator-identification enable command is run and authentication of another type is configured or no authentication is configured, generated Purge LSPs carry the POI TLV and hostname TLV.
For the sake of security, using the HMAC-SHA256 algorithm rather than the HMAC-MD5 algorithm is recommended.
If the purge-originator-identification enable always command is run, generated Purge LSPs carry the POI TLV and hostname TLV, regardless of whether authentication is configured or whether the send-only parameter is specified when configuring authentication.

Prerequisites

An IS-IS process has been created and the IS-IS view has been displayed using the isis command.

Configuration Impact

This command requires that all IS-IS devices on the network support standard protocol. If any IS-IS device does not support standard protocol, a routing loop or black hole may occur.

Example

# Configure IS-IS to add POI TLV to Purge packets.

<HUAWEI> system-view
[~HUAWEI] isis 1
[*HUAWEI-isis-1] purge-originator-identification enable