3Com 10014299 manual Troubleshooting IP Performance Configuration

364CHAPTER 22: CONFIGURING IP PERFORMANCE

Troubleshooting IP

Performance

Configuration

Fault 1: TCP and UDP are created upon IP protocol, and IP is able to provide data packet transmission. However, TCP and UDP protocols do not work normally

Troubleshooting: Turn on corresponding debugging switches to check the debugging information

■Use the debugging udp command to turn on the UDP debugging switch, and trace the UDP data packet. When the router sends or receives UDP data packets, the packet content format can be displayed in real time, so problems can be located.

The UDP data packet format is as follows:

UDP output packet:

Source IP address: 202.38.160.1

Source port: 1024

Destination IP Address 202.38.160.1

Destination port: 4296

■Use the debugging tcp command to turn on the TCP debugging switch, and trace the TCP data packet. TCP has two data packet format options: one is to debug and trace the receiving/sending of TCP packets in all TCP connections with this equipment as one end. The specific operation is as follows:

[Router] info-center enable

[Router] debugging tcp packet

The TCP packets received or sent can be checked in real time, and the specific format is as follows:

TCP output packet:

Source IP address: 202.38.160.1

Source port: 1024

Destination IP Address 202.38.160.1

Destination port: 4296

Sequence number: 4185089

Ack number: 0

Flag: SYN

Packet length: 60

Data offset: 10

Another data packet format is to debug and trace packets with SYN, FIN or RST setting.

[Router] info-center enable

[Router] debugging tcp event

The TCP packets received or sent can be checked in real time, with the same packet format as above.