Adjust the TCP Maximum Segment Size

Adjust the TCP maximum segment size (MSS) to improve the throughput for the TCP session over a Fabric Extend (FE) adjacency.

About this task

The default value, when enabled, is 1300.

Procedure

  1. Enter Global Configuration mode:

    enable

    configure terminal

  2. Use one of the following commands to configure the MSS adjustment functionality as required:
    1. Configure an explicit MSS adjust value:

      ip tcp adjust-mss <500-1900> [enable]

    2. Disable MSS adjustment explicitly:

      no ip tcp adjust-mss enable

  3. Verify the configuration:

    show ip tcp adjust-mss

Examples

Configure an MSS value of 1100 and verify the configuration.

Switch:1>enable
Switch:1#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch:1(config)#ip tcp adjust-mss 1200
Switch:1>show ip tcp adjust-mss
================================================================================
                              IP TCP Adjust MSS
================================================================================
ENABLE            STATUS            TCP MSS                   TCP MSS
                                    TYPE                      VALUE
--------------------------------------------------------------------------------
TRUE              ACTIVE            MANUAL-CONFIG             1200