tcp adjust-mss

Function

The tcp adjust-mss command sets the maximum segment size (MSS) that can be sent to the peer in a TCP session.

The undo tcp adjust-mss command restores the default MSS value.

By default, the TCP MSS value is 0, and the device does not process the packet.

This command is supported only on the NetEngine 8000 F1A.

Format

tcp adjust-mss mss-value

undo tcp adjust-mss

Parameters

Parameter	Description	Value
mss-value	specifies the TCP MSS value.	The value is an integer ranging from 1 to 8978.

Parameter

Description

Value

mss-value

specifies the TCP MSS value.

The value is an integer ranging from 1 to 8978.

Views

Virtual template view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
l2tp	write

Usage Guidelines

Usage Scenario

MSS is the maximum size of a packet that can be sent in a TCP session. After a TCP session is established, the local end and the peer end send their MSS values to each other.

If the MSS is set, the maximum length of an IP packet is the total of MSS, length of the IP header (20 bytes), and length of the TCP header (20 bytes). The maximum length of an IP packet is also limited by the MTU; therefore, if calculated maximum length exceeds the MTU, the packet is fragmented. To improve the efficiency of packet transmission, it is recommended to set a large TCP MSS value, but ensure that the packets will not be fragmented.

Precautions

In VS mode, this command is supported only by the admin VS.

Example

# Set the TCP MSS of VT 4 to 1460.

<HUAWEI> system-view
[~HUAWEI] interface virtual-template 4
[*HUAWEI-Virtual-Template4] tcp adjust-mss 1460