R0106-HP MSR Router Series Layer 3 - IP Services Command Reference(V7)

228
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 GigabitEthernet 2/1/1.
<Sysname> system-view
[Sysname] interface gigabitethernet 2/1/1
[Sysname-GigabitEthernet2/1/1] 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.
Usage guidelines
After you enable TCP path MTU discovery, all new TCP connections detect the path MTU. The device uses
the path MTU to calculate the MSS to avoid IP fragmentation.
After you disable TCP path MTU discovery, the system stops all path MTU timers. The TCP connections
established later do not detect the path MTU, but the TCP connections previously established still can
detect the path MTU.
Examples
# Enable TCP path MTU discovery and set the path MTU aging time to 20 minutes.
<Sysname> system-view
[Sysname] tcp path-mtu-discovery aging 20
tcp syn-cookie enable
Use tcp syn-cookie enable to enable SYN Cookie to protect the device from SYN flood attacks.
Use undo tcp syn-cookie enable to disable SYN Cookie.