4000 Router Series Layer 3 - IP Services Command Reference

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Predefined user roles

network-admin

Parameters

Value: Specifies the TCP MSS in the range of 128 to 2048 bytes.

Usage guidelines

This configuration takes effect only on TCP connections that are established after the configuration and

not on the TCP connections that already exist.

This configuration is effective only on IP packets. If MPLS is enabled on the interface, do not configure the

TCP MSS on the interface.

The MSS option informs the receiver of the largest segment that the sender can accept. Each end

announces its MSS during TCP connection establishment.

If the size of a TCP segment is smaller than the MSS of the receiver, TCP sends the TCP segment without

fragmentation. If not, it fragments the segment according to the receiver's MSS.

If you configure a TCP MSS on an interface, the size of each TCP segment received or sent on the

interface cannot exceed the MSS value.

Examples

# Set the TCP MSS to 300 bytes on Ethernet 1/1.

<Sysname> system-view

[Sysname] interface ethernet 1/1

[Sysname-Ethernet1/1] tcp mss 300

tcp path-mtu-discovery

Use tcp path-mtu-discovery to enable TCP path MTU discovery.

Use undo tcp path-mtu-discovery to disable TCP path MTU discovery.

Syntax

tcp path-mtu-discovery [ aging age-time | no-aging ]

undo tcp path-mtu-discovery

Default

TCP path MTU discovery is disabled.

Views

System view

Predefined user roles

network-admin

Parameters

aging age-time: Sets the aging time for the path MTU, in the range of 10 to 30 minutes. The default

aging time is 10 minutes.

no-aging: Does not age out the path MTU.