label-withdraw-delay

Function

The label-withdraw-delay command enables a node to delay sending Label Withdraw messages.

The undo label-withdraw-delay command disables a node from delaying sending Label Withdraw messages.

By default, the label withdraw delay function is disabled.

Format

label-withdraw-delay

undo label-withdraw-delay

Parameters

None

Views

MPLS-LDP view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

The label withdraw delay function prevents downstream LSP flapping from spreading to upstream nodes. For example, an LSP on a local node flaps because an LDP session between the node and its downstream peer flaps, a route flaps, or an LDP policy is modified. The local node repeatedly sends Label Withdraw and Label Mapping messages in sequence to upstream nodes. This causes the upstream nodes to repeatedly tear down and reestablish LSPs. As a result, the entire LDP LSP flaps. The label withdraw delay function can be enabled on each node of the LDP LSP to suppress the spread of LSP flapping.

Follow-up Procedure

Use the default delay time of 5s or run the label-withdraw-delay timer command to set the delay time.

Example

# Enable the label withdraw delay function.

<HUAWEI> system-view
[HUAWEI] mpls ldp
[HUAWEI-mpls-ldp] label-withdraw-delay