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

Note

If you downgrade to an earlier release that does not support this feature, you must disable the feature and save the configuration. Downgrading to an earlier release requires a compatible configuration file.

The default value, when enabled, is 1300.

Procedure

Enter Global Configuration mode:

enable

configure terminal
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 <max-segment-size> [enable]
2. Disable MSS adjustment explicitly:
  
  no ip tcp adjust-mss enable
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