3Com 9100 manual Enable qosmonitor port port, Disable qosmonitor

108CHAPTER 7: QUALITY OF SERVICE (QOS)

QoS monitor sampling is configured as follows:

■The port is monitored for 20 seconds before the switch moves on to the next port in the list.

■A port is sampled for five seconds before the packets per second (pps) value is displayed on the screen.

Monitoring QoS in the background places transmit counter and any “overflow” information into the switch log. The log notification appears if one of the queues experiences an overflow condition since the last time it was sampled. An overflow entry indicates that a queue was over-subscribed at least temporarily, and is useful for determining correct QoS settings and potential over-subscription issues. Table 28 describes the QoS monitor commands.

Table 28 QoS Monitor Commands

Command	Description
enable qosmonitor {port <port>}	Enables the QoS monitoring capability on the
	switch. When no port is specified, the QoS
	monitor automatically samples all the ports.
	Error messages are logged to the syslog if the
	traffic exceeds the parameters of the QoS
	profile(s). The default setting is disabled.
disable qosmonitor	Disables the QoS monitoring capability.
show ports {<portlist>} qosmonitor	Displays real-time QoS statistics for one or
	more ports.

Modifying a QoS If you make a change to the parameters of a QoS profile after a QoS

Policypolicy has already been formed (by applying a QoS profile to a traffic grouping), the timing of the configuration change depends on the traffic grouping involved. To have a change in QoS profile effect a change in the QoS policy, the following rules apply:

■For destination MAC-based grouping (other than permanent), clear the MAC FDB using the command clear fdb. This command should also be issued after a policy is first formed, as the policy must be in place before an entry is made in the MAC FDB. For permanent destination MAC-based grouping, re-apply the QoS profile to the static FDB entry. You can also save and reboot the switch.