User guide

Configuring QoS Configuring Global QoS Parameters
OmniSwitch 6600 Family Network Configuration Guide April 2005 page 23-13
Configuring Global QoS Parameters
This section describes the global QoS configuration, which includes enabling and disabling QoS, apply-
ing and activating the configuration, controlling the QoS log display, and configuring QoS port and queue
parameters.
Enabling/Disabling QoS
By default QoS is enabled on the switch. If QoS policies are configured and applied, the switch will
attempt to classify traffic and apply relevant policy actions.
To disable the QoS, use the qos command. For example:
-> qos disable
QoS is immediately disabled. When QoS is disabled globally, any flows coming into the switch are not
classifed (matched to policies).
To re-enable QoS, enter the qos command with the enable option:
-> qos enable
QoS is immediately re-enabled. Any policies that are active on the switch will be used to classify traffic
coming into the switch.
Note that individual policy rules may be enabled or disabled with the policy rule command.
Setting the Global Default Dispositions
By default, bridged, routed, and multicast flows that do not match any policies are accepted on the switch.
To change the global default disposition (which determines whether the switch will accept, deny, or drop
the flow), use the desired disposition setting (accept, drop, or deny) with any of the following commands:
qos default bridged disposition, qos default routed disposition, or qos default multicast disposition.
In the current release, the drop and deny options produce the same result (flows are silently dropped; no
ICMP message is sent).
For example, to deny any routed flows that do not match policies, enter:
-> qos default routed disposition deny
To activate the setting, enter the qos apply command. For more information about the qos apply
command, see “Applying the Configuration” on page 23-47.
Typically, the disposition is only configured when you are using policies for Access Control Lists (ACLs).
Note that if you set qos default bridged disposition to deny, you effectively drop all traffic (bridged or
routed) that does not match any policy. If you want to create ACLs to allow some Layer 2 traffic through
the switch, you must configure two rules for each type of Layer 2 traffic, one for source and one for desti-
nation. For more information about ACLs, see Chapter 24, “Configuring ACLs.”