3Com Switch 7757, Configuration Manual

Page: 131 / 940

16
IP P
ERFORMANCE
C
ONFIGURATION
IP Performance
Overview
Introduction to TCP
Attributes
IP performance configuration mainly refers to TCP attribute configuration. The
TCP attributes that can be configured include:
■
synwait timer: This timer is started when TCP sends a syn packet. If no response
packet is received before the timer times out, the TCP connection will be
terminated. The timeout of the synwait timer ranges from 2 to 600 seconds
and is 75 seconds by default.
■
finwait timer: This timer is started when the TCP connection turns from the
FIN_WAIT_1 state to the FIN_WAIT_2 state. If no FIN packet is received before
the timer times out, the TCP connection will be terminated. The timeout of the
finwait timer ranges from 76 to 3,600 seconds and is 675 seconds by default.
■
The connection-oriented socket receive/send buffer size ranges from 1 to 32
KB and is 8 KB by default.
Introduction to FIB Every switch stores a forwarding information base (FIB). FIB is used to store the
forwarding information of the switch and guide Layer 3 packet forwarding.
You can know the forwarding information of the switch through the FIB table.
Each FIB entry includes: destination address/mask length, next hop, current flag,
timestamp, and outbound interface.
When the switch is running normally, the contents of the FIB and the routing table
are the same. For routing and routing tables, refer to “Routing Table” on page
281.
IP Performance
Configuration
Table 76 Configure IP
Configuration task Description Detailed configuration
Configure TCP attributes Required “Configuring TCP Attributes”
on page 132
Configure to send special IP packets
to CPU Required “Configuring to Send Special IP
Packets to CPU” on page 132
Enable forwarding of directed
broadcasts to a directly connected
network Required “Enabling Forwarding of
Directed Broadcasts to a
Directly Connected Network”
on page 132
Disable ICMP error message sending Required “Disabling ICMP Error Message
Sending” on page 133