mtu-signalling

Function

The mtu-signalling command enables the switch to send Label Mapping messages carrying the MTU TLV and determines the MTU TLV type.

The undo mtu-signalling command disables the switch to send Label Mapping messages carrying the MTU TLV

By default, the switch with MPLS LDP globally enabled sends Label Mapping messages carrying the MTU TLV, in compliance with draft-ietf-mpls-ldp-mtu-extensions.

Format

mtu-signalling [ apply-tlv ]

undo mtu-signalling [ apply-tlv ]

Parameters

Parameter	Description	Value
apply-tlv	Indicates the type of MTU TLV carried in Label Mapping messages to be sent. After this parameter is configured, the implementation is in compliance with RFC 3988. If this parameter is not configured, the implementation is in compliance with draft-ietf-mpls-ldp-mtu-extensions.	-

Views

MPLS-LDP view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

If different types of links on an MPLS network support different MTU values, this function enables devices to negotiate MTU values, prevents packets from being discarded if the packet size exceeds an MTU.

Prerequisites

MPLS LDP has been enabled globally using the mpls ldp command in the system view.

Precautions

By default, after MPLS LDP is globally enabled, a device sends Label Mapping messages carrying an MTU TLV in compliance with draft-ietf-mpls-ldp-mtu-extensions. If an LDP peer does not identify the MTU TLV carried in a received message, the peer must process the TLV as an unknown TLV defined in RFC 5036.

Changing the configuration disconnects an existing LDP session and causes the LDP session to be reestablished.

Example

# Enable LDP to send Label Mapping messages carrying the MTU TLV, as defined in RFC3988.

<HUAWEI> system-view
[HUAWEI] mpls ldp
[HUAWEI-mpls-ldp] mtu-signalling apply-tlv
Warning: All the related sessions will be deleted if the operation is performed!Continue? (y/n)y