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
A 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 interface.
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 a 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
Configuring Priority-Based Flow Control
As soon as you apply a DCB map with PFC enabled on an interface, DCBx starts exchanging information with a peer. The IEEE802.1Qbb,
CEE and CIN versions of PFC TLV are supported. DCBx also validates PFC configurations that are received in TLVs from peer devices. By
applying a DCB map with PFC enabled, you enable PFC operations on ingress port traffic. To achieve complete lossless handling of traffic,
configure PFC priorities on all DCB egress ports.
When you apply or remove a DCB input policy from an interface, one or two CRC errors are expected to be noticed on the ingress ports for
each removal or attachment of the policy. This behavior occurs because the port is brought down when PFC is configured. When a DCB
input policy with PFC profile is configured or unconfigured on an interface or a range of interfaces not receiving any traffic, interfaces with
PFC settings that receive appropriate PFC-enabled traffic (unicast, mixed-frame-size traffic) display incremental values in the CRC and
discards counters. (These ingress interfaces receiving pfc-enabled traffic have an egress interface that has a compatible PFC
configuration).
NOTE:
DCB maps are supported only on physical Ethernet interfaces.
•
To remove a DCB map, including the PFC configuration it contains, use the
no dcb map
command in Interface configuration mode.
260
Data Center Bridging (DCB)
Содержание S4048T-ON
Страница 1: ...Dell Configuration Guide for the S4048 ON System 9 11 2 1 ...
Страница 148: ...Figure 10 BFD Three Way Handshake State Changes 148 Bidirectional Forwarding Detection BFD ...
Страница 251: ...Dell Control Plane Policing CoPP 251 ...
Страница 363: ... RPM Synchronization GARP VLAN Registration Protocol GVRP 363 ...
Страница 511: ...Figure 64 Inspecting the LAG Configuration Link Aggregation Control Protocol LACP 511 ...
Страница 512: ...Figure 65 Inspecting Configuration of LAG 10 on ALPHA 512 Link Aggregation Control Protocol LACP ...
Страница 515: ...Figure 67 Inspecting a LAG Port on BRAVO Using the show interface Command Link Aggregation Control Protocol LACP 515 ...
Страница 516: ...Figure 68 Inspecting LAG 10 Using the show interfaces port channel Command 516 Link Aggregation Control Protocol LACP ...
Страница 558: ...Figure 84 Configuring Interfaces for MSDP 558 Multicast Source Discovery Protocol MSDP ...
Страница 559: ...Figure 85 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 559 ...
Страница 560: ...Figure 86 Configuring PIM in Multiple Routing Domains 560 Multicast Source Discovery Protocol MSDP ...
Страница 564: ...Figure 88 MSDP Default Peer Scenario 2 564 Multicast Source Discovery Protocol MSDP ...
Страница 565: ...Figure 89 MSDP Default Peer Scenario 3 Multicast Source Discovery Protocol MSDP 565 ...
Страница 729: ...protocol spanning tree pvst no disable vlan 300 bridge priority 4096 Per VLAN Spanning Tree Plus PVST 729 ...
Страница 841: ...Figure 115 Single and Double Tag TPID Match Service Provider Bridging 841 ...
Страница 842: ...Figure 116 Single and Double Tag First byte TPID Match 842 Service Provider Bridging ...