bgp-lsp mtu (BGP-VPN instance IPv4 address family view/BGP-labeled VPN instance IPv4 address family view)

Function

The bgp-lsp mtu command sets an MTU for BGP LSPs.

The undo bgp-lsp mtu command restores the default MTU of BGP LSPs.

By default, the MTU of BGP LSPs is 1500.

Format

bgp-lsp mtu lspmtuVal

undo bgp-lsp mtu

Parameters

Parameter	Description	Value
lspmtuVal	Specifies the MTU for BGP LSPs.	The value is an integer ranging from 46 to 65535.

Parameter

Description

Value

lspmtuVal

Specifies the MTU for BGP LSPs.

The value is an integer ranging from 46 to 65535.

Views

BGP-labeled VPN instance IPv4 address family view, BGP-VPN instance IPv4 address family view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
bgp	write

Usage Guidelines

Usage Scenario

An MTU value determines the maximum number of bytes of a packet each time a sender can send without fragmenting the packet. If the size of packets exceeds the MTU supported by a transit node or a receiver, the transit node or receiver fragments the packets or even discards them, aggravating the network transmission load. MTU values must be correctly negotiated between LSRs to allow packets to successfully reach the receiver.

Example

# Set the MTU to 20000 for BGP LSPs.

<HUAWEI> system-view
[~HUAWEI] ip vpn-instance vpna
[*HUAWEI-vpn-instance-vpna] ipv4-family
[*HUAWEI-vpn-instance-vpna-af-ipv4] route-distinguisher 1:1
[*HUAWEI-vpn-instance-vpna-af-ipv4] quit
[*HUAWEI-vpn-instance-vpna] quit
[*HUAWEI] bgp 100
[*HUAWEI-bgp] ipv4-family vpn-instance vpna
[*HUAWEI-bgp-vpna] bgp-lsp mtu 20000