mpls l2vpn pw-ttl

Function

The mpls l2vpn pw-ttl command configures the TTL value of a PW.

The undo mpls l2vpn pw-ttl command restores the default TTL value of a PW.

By default, the TTL value of a PW is 1.

Format

mpls l2vpn pw-ttl ttlValue [ bypass | secondary ]

undo mpls l2vpn pw-ttl ttlValue [ bypass | secondary ]

Parameters

Parameter	Description	Value
ttlValue	Specifies the TTL value (number of PW segments from end to end) for a PW.	The value is an integer ranging from 1 to 255.
bypass	Configures the TTL value for the bypass PW.	-
secondary	Configures the TTL value for the secondary PW.	-

Parameter

Description

Value

ttlValue

Specifies the TTL value (number of PW segments from end to end) for a PW.

The value is an integer ranging from 1 to 255.

bypass

Configures the TTL value for the bypass PW.

secondary

Configures the TTL value for the secondary PW.

Views

100ge sub-interface view, 100GE interface view, 10GE sub-interface view, 10GE interface view, 200GE sub-interface view, 25GE sub-interface view, 25GE interface view, 400GE Layer 2 sub-interface view, 400GE sub-interface view, 400GE interface view, 40GE sub-interface view, 40GE interface view, 50GE Layer 2 sub-interface view, 50GE sub-interface view, 50GE interface view, Eth-Trunk Layer 2 sub-interface view, Eth-Trunk sub-interface view, Eth-Trunk interface view, GE Layer 2 sub-interface view, GE optical interface view, GE sub-interface view, GE interface view, GE electrical interface view, Global VE sub-interface view, VE sub-interface view, XGE sub-interface view, XGE interface view, Layer 2 sub-interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
l2vpn	write

Usage Guidelines

Usage Scenario

A static multi-segment PW (MS-PW) or a hybrid MS-PW cannot obtain the TTL value by dynamic negotiation. To ensure that PW APS negotiation packets are forwarded correctly between the PEs on the two ends of a PW, manually configure a TTL value so that the APS module will be informed of the number of segments from end to end on the PW.

The TTL value does not need to be manually configured in the following situations:

The TTL value defaults to 1 if the PW is a single-segment one.
If the PW is a dynamic multi-segment one, the TTL value can be automatically calculated based on the PW negotiation signaling and does not need to be manually configured. If you configure a TTL value manually, the configured TTL value takes precedence over the automatically calculated one.

Prerequisites

The specified primary, secondary, or bypass PW has been configured in the interface view.

Configuration Impact

The TTL value is used during the forwarding of PW APS negotiation packets.

Precautions

The TTL value specified in the undo mpls l2vpn pw-ttl command must equal the number of PW segments.

Only the NetEngine 8000 F1A supports PW APS.

Example

# Configure the TTL value for a PW protection group in the interface view.

<HUAWEI> system-view
[~HUAWEI] mpls
[*HUAWEI-mpls] quit
[*HUAWEI] mpls l2vpn
[*HUAWEI-l2vpn] quit
[*HUAWEI] interface GigabitEthernet 0/1/0
[*HUAWEI-GigabitEthernet0/1/0] mpls l2vpn pw-ttl 12
[*HUAWEI-GigabitEthernet0/1/0] mpls l2vpn pw-ttl 13 secondary