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NOTE: Although, each port on the S4810, S4820T, and S5000 devices support 8 QoS queues, you can configure only 4
QoS queues (0-3) to manage data traffic. The remaining 4 queues (4-7) are reserved for control traffic.
Dell(conf)#do show qos dot1p-queue-mapping
Dot1p Priority : 0 1 2 3 4 5 6 7
Queue : 0 0 0 1 2 3 3 3
Dell(conf)#
The configuration of no-drop queues provides flexibility for ports on which PFC is not needed but lossless traffic should egress from
the interface.
Lossless traffic egresses out the no-drop queues. Ingress dot1p traffic from PFC-enabled interfaces is automatically mapped to the
no-drop egress queues.
1.
Enter INTERFACE Configuration mode.
CONFIGURATION mode
interface type
slot/port
[
/subport
]
2.
Configure the port queues that will still function as no-drop queues for lossless traffic.
INTERFACE mode
pfc no-drop queues
queue-range
For the dot1p-queue assignments, refer to the dot1p Priority-Queue Assignment table.
The maximum number of lossless queues globally supported on the switch is two.
The range is from 0 to 3. Separate the queue values with a comma; specify a priority range with a dash; for example,
pfc no-
drop queues 1,3
or
pfc no-drop queues 2-3
.
The default: No lossless queues are configured.
NOTE: Dell Networking OS Behavior: By default, no lossless queues are configured on a port.
A limit of two lossless queues is supported on a port. If the amount of priority traffic that you configure to be paused exceeds the
two lossless queues, an error message displays.
Configuring PFC in a DCB Map
An S4048–ON switch supports the use of a DCB map in which you configure priority-based flow control (PFC) setting. To configure
PFC parameters, you must apply a DCB map on an S4048–ON interface. This functionality is supported on the S4048–ON platform.
PFC Configuration Notes
PFC provides flow control based on the 802.1p priorities in a converged Ethernet traffic that is received on an interface and is
enabled by default when you enable DCB. As an enhancement to the existing Ethernet pause functionality, PFC stops traffic
transmission for specified priorities (CoS values) without impacting other priority classes. Different traffic types are assigned to
different priority classes.
When traffic congestion occurs, PFC sends a pause frame to a peer device with the CoS priority values of the traffic that needs to
be stopped. DCBx provides the link-level exchange of PFC parameters between peer devices. PFC allows network administrators to
create zero-loss links for SAN traffic that requires no-drop service, while at the same time retaining packet-drop congestion
management for LAN traffic.
On switch, PFC is enabled by default on Ethernet ports (
pfc mode on
command). You can configure PFC parameters using a
DCB map or the
pfc priority
command in Interface configuration mode. For more information, see
248
Data Center Bridging (DCB)
Содержание S4048-ON
Страница 1: ...Dell Configuration Guide for the S4048 ON System 9 9 0 0 ...
Страница 146: ...Figure 14 BFD Three Way Handshake State Changes 146 Bidirectional Forwarding Detection BFD ...
Страница 477: ...Figure 68 Inspecting Configuration of LAG 10 on ALPHA Link Aggregation Control Protocol LACP 477 ...
Страница 480: ...Figure 70 Inspecting a LAG Port on BRAVO Using the show interface Command 480 Link Aggregation Control Protocol LACP ...
Страница 481: ...Figure 71 Inspecting LAG 10 Using the show interfaces port channel Command Link Aggregation Control Protocol LACP 481 ...
Страница 522: ...Figure 87 Configuring Interfaces for MSDP 522 Multicast Source Discovery Protocol MSDP ...
Страница 523: ...Figure 88 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 523 ...
Страница 524: ...Figure 89 Configuring PIM in Multiple Routing Domains 524 Multicast Source Discovery Protocol MSDP ...
Страница 528: ...Figure 91 MSDP Default Peer Scenario 1 528 Multicast Source Discovery Protocol MSDP ...
Страница 529: ...Figure 92 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 529 ...
Страница 530: ...Figure 93 MSDP Default Peer Scenario 3 530 Multicast Source Discovery Protocol MSDP ...
Страница 633: ...Policy based Routing PBR 633 ...
Страница 777: ...Figure 119 Single and Double Tag TPID Match Service Provider Bridging 777 ...
Страница 778: ...Figure 120 Single and Double Tag First byte TPID Match 778 Service Provider Bridging ...