cache-sa-enable

Function

The cache-sa-enable command enables the SA cache function on a switch. After receiving an SA message, the switch caches (S, G) information carried in the SA message.

The cache-sa-disable command disables the SA cache function.

The undo cache-sa-enable command disables the SA cache function.

By default, the SA cache function is enabled on a switch.

Format

cache-sa-enable

cache-sa-disable

undo cache-sa-enable

Parameters

None

Views

MSDP view of the public network instance or MSDP view of the VPN instance

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

A switch enabled with the SA cache function locally saves (S, G) information carried in the received SA messages. When the switch receives requests for receiving multicast data, it directly obtains (S, G) information from the SA cache.

A switch no longer saves (S, G) information carried in the received SA messages locally after the undo cache-sa-enable or the cache-sa-disable command is run to disable the SA cache function. When the switch receives requests for receiving multicast data, it must wait for the SA messages sent by the MSDP peer in the next sending period. This may result in a delay in receiving multicast data.

Prerequisites

MSDP has been enabled using the msdp command.

Configuration Impact

When an RP receives a new (*, G) Join message,

If the SA cache function is enabled, the RP searches the SA cache for the (S, G) information.
- If the SA cache contains related (S, G) information, the RP directly joins the SPT with the root being S.
- If the SA cache does not contain related (S, G) information, the RP does not process the received Join message.
If the SA cache function is disabled, the RP processes the message in one of the following ways:
- If the sending of SA Request messages is enabled, the RP sends an SA Request message to the specified MSDP peer and waits for the response.
- If the sending of SA Request messages is disabled, the RP must wait for the SA message sent by the MSDP peer in the next sending period.

Precautions

The cache-sa-disable and undo cache-sa-enable commands' configurations are both undo cache-sa-enable in the configuration file.

Example

# Disable the SA cache function on the switch.

<HUAWEI> system-view
[HUAWEI] multicast routing-enable
[HUAWEI] msdp
[HUAWEI-msdp] undo cache-sa-enable