peer tcp-mss (BGP-VPN instance IPv4 address family view) (group)

Function

The peer tcp-mss command configures a TCP MSS value used when the local device establishes TCP connections with a peer group.

The undo peer tcp-mss command deletes the configured TCP MSS value.

By default, no TCP MSS is configured for the local device to establish TCP connections with a peer group.

Format

peer group-name tcp-mss tcp-mss-number

undo peer group-name tcp-mss

Parameters

Parameter	Description	Value
group-name	Specifies the name of a peer group.	The name is a string of 1 to 47 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string.
tcp-mss-number	Specifies the TCP MSS value used for TCP connection establishment.	The value is an integer ranging from 176 to 4096, in bytes.

Parameter

Description

Value

group-name

Specifies the name of a peer group.

The name is a string of 1 to 47 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string.

tcp-mss-number

Specifies the TCP MSS value used for TCP connection establishment.

The value is an integer ranging from 176 to 4096, in bytes.

Views

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

You can run the peer tcp-mss command to configure a TCP MSS value used for TCP connection establishment so that it is used to encapsulate BGP packets when the path MTU is unavailable. Such configuration improves network performance.

Precautions

If you change the tcp-mss-number value, the TCP connection will be re-established.

If both the peer tcp-mss and peer path-mtu auto-discovery commands are run, note the following rules:

If the local device obtains the path MTU, the smaller value of TCP MSS and path MTU takes effect.
If the local device fails to obtain the path MTU, TCP MSS takes effect.

Example

# Configure a TCP MSS value for the local device to establish TCP connections with the peer group.

<HUAWEI> system-view
[~HUAWEI] ip vpn-instance vpn1
[*HUAWEI-vpn-instance-vpn1] ipv4-family
[*HUAWEI-vpn-instance-vpn1-af-ipv4] route-distinguisher 100:1
[*HUAWEI-vpn-instance-vpn1-af-ipv4] quit
[*HUAWEI-vpn-instance-vpn1] quit
[*HUAWEI] bgp 100
[*HUAWEI-bgp] ipv4-family vpn-instance vpn1
[*HUAWEI-bgp-vpn1] group test
[*HUAWEI-bgp-vpn1] peer test tcp-mss 200