AIX 5L Problem Determination - IBM Redbooks

those that do not. If you are running a program that does a considerable amount
of remote reads and writes and it is running slowly, but everything else seems to
be running normally, then it is probably a network problem. Some of the potential
network bottlenecks can be caused by the following:
► Client-network interface
► Network bandwidth
► Network topology
► Server network interface
► Server CPU load
► Server memory usage
► Server bandwidth
► Inefficient configuration
A large part of network tuning involves tuning TCP/IP to achieve maximum
throughput. With the new high bandwidth interfaces such as Gigabit Ethernet,
this has become even more important.
The first command to use for gathering information on network performance is
the netstat command.
10.4.1 The netstat command
The netstat command is used to show network status. Traditionally, it is used
more for problem determination than for performance measurement. However,
the netstat command can be used to determine the amount of traffic on the
network, which can help determine whether performance problems are due to
network congestion.
The netstat -i command
The netstat -i command shows the state of all configured interfaces.
The following example shows the statistics for a workstation with an integrated
Ethernet and a token-ring adapter:
# netstat -i
Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll
lo0 16896 144834 0 144946 0 0
lo0 16896 127 localhost 144834 0 144946 0 0
tr0 1492 10.0.5a.4f.3f.61 658339 0 247355 0 0
tr0 1492 9.3.1 ah6000d 658339 0 247355 0 0
en0 1500 8.0.5a.d.a2.d5 0 0 112 0 0
en0 1500 1.2.3 1.2.3.4 0 0 112 0 0
266 IBM ^ Certification Study Guide - AIX 5L Problem Determination Tools and Techniques