H3C Technologies H3C SecPath F1000-E - Manual (Page 24)

4
Configuring TCP Attributes
Configuring TCP MSS for the Interface
The Max Segment Size (MSS) option informs the receiver of the largest segment that the sender is willing
to accept. Each end announces the MSS it expects to receive during the TCP connection establishment.
The end that receives the MSS value from the other end then limits the size of each TCP segment to be
sent. If the size of a TCP segment is smaller than the MSS of the other end, the TCP segment is sent to the
other end without being fragmented; otherwise, it will be fragmented according to the MSS before being
sent.
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.
Follow these steps to configure TCP MSS of the interface:
To do… Use the command… Remarks
Enter system view system-view —
Enter interface view
interface interface-type
interface-number
—
Configure the TCP MSS of the
interface
tcp mss value
Optional
The TCP MSS is 1460 bytes by
default.
NOTE:
•
This configuration takes effect only on TCP connections that are established after the configuration rather
than the TCP connections that already exist.
• This configuration is effective only on IP packets. If MPLS is enabled on the interface, you are not
recommended to configure the TCP MSS on the interface.
Configuring the TCP Send/Receive Buffer Size
Follow these steps to configure the TCP send/receive buffer size:
To do… Use the command… Remarks
Enter system view system-view —
Configure the size of TCP
receive/send buffer
tcp window window-size
Optional
8 KB by default.
Configuring TCP Timers
You can configure the following TCP timers:
• synwait timer: When sending a SYN packet, TCP starts the synwait timer. If no response packet is
received within the synwait timer interval, the TCP connection cannot be created.