The tcp ipv6 max-mss command sets the maximum value of Maximum Segment Size (MSS) for a TCP6 connection.
The undo tcp ipv6 max-mss command deletes the maximum MSS value of a TCP6 connection.
By default, the maximum MSS value is not configured for TCP6 connections.
| Parameter | Description | Value |
|---|---|---|
| mss-value | Specifies the maximum MSS value for a TCP6 connection. | The value is an integer ranging from 32 to 9600, in bytes. |
Usage Scenario
To establish a TCP6 connection, the MSS value is negotiated, which indicates the maximum length of packets that the local device can receive. If the path MTU is unavailable on one end of a TCP6 connection, this end cannot adjust the TCP6 packet size based on the MTU. As a result, this end may send TCP6 packets that are longer than the MTUs on intermediate devices, which will discard these packets. To prevent this problem, run the tcp ipv6 max-mss command on either end of a TCP6 connection to set the maximum MSS value of TCP6 packets. Then the MSS value negotiated by both ends will not exceed this maximum MSS value, and accordingly TCP6 packets sent from both ends will not be longer than this maximum MSS value and can travel through the intermediate network.
Precautions
The maximum MSS value configured using the tcp ipv6 max-mss command must be greater than the minimum MSS value configured using the tcp ipv6 min-mss command.