Policy for Fibre Channel Interfaces
The egress queues are not configurable for native Fibre Channel interfaces. Two queues are available as
follows:
•
A strict priority queue to serve high-priority control traffic.
•
A queue to serve all data traffic and low-priority control traffic.
QoS for Multicast Traffic
By default, all multicast Ethernet traffic is classified into the default drop system class. This traffic is serviced
by one multicast queue.
Optimized multicasting allows use of the unused multicast queues to achieve better throughput for multicast
frames. If optimized multicast is enabled for the default drop system class, the system will use all 128 queues
to service the multicast traffic. When optimized multicast is enabled for the default drop system class, all 128
queues are given equal priority.
If you define a new system class, a dedicated multicast queue is assigned to that class. This queue is removed
from the set of queues available for the optimized multicast class.
The system provides two predefined class maps for matching broadcast or multicast traffic. These class maps
are convenient for creating separate policy maps for unicast and multicast traffic.
The predefined class maps are as follows:
class-all-flood
The class-all-flood class map matches all broadcast, multicast, and unknown unicast traffic (across all
CoS values). If you configure a policy map with the class-all-flood class map, the system automatically
uses all available multicast queues for this traffic.
class-ip-multicast
The class-ip-multicast class map matches all IP multicast traffic. Policy options configured in this class
map apply to traffic across all Ethernet CoS values. For example, if you enable optimized multicast for
this class, the IP multicast traffic for all CoS values is optimized.
If you configure either of these predefined class maps as a no-drop class, the priority flow control capability
is applied across all Ethernet CoS values. In this configuration, pause will be applied to unicast and
multicast traffic.
Note
Cisco Nexus 5000 NX-OS Quality of Service Configuration Guide, Release 5.1(3)N2(1)
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Configuring QoS on Interfaces
Policy for Fibre Channel Interfaces
