- play_arrow Weighted Random Early Detection (WRED) and Explicit Congestion Notification (ECN)
- play_arrow WRED and Drop Profiles
- play_arrow Explicit Congestion Notification (ECN)
-
- play_arrow CoS Queue Schedulers, Traffic Control Profiles, and Hierarchical Port Scheduling (ETS)
- play_arrow Queue Schedulers and Scheduling Priority
- Understanding Default CoS Scheduling and Classification
- Understanding CoS Scheduling Behavior and Configuration Considerations
- Understanding CoS Output Queue Schedulers
- Defining CoS Queue Schedulers
- Example: Configuring Queue Schedulers
- Defining CoS Queue Scheduling Priority
- Example: Configuring Queue Scheduling Priority
- Monitoring CoS Scheduler Maps
- play_arrow Port Scheduling and Shaping
- play_arrow Troubleshooting Egress Bandwidth Issues
- play_arrow Traffic Control Profiles and Priority Group Scheduling
- Understanding CoS Traffic Control Profiles
- Understanding CoS Priority Group Scheduling
- Understanding CoS Virtual Output Queues (VOQs)
- Defining CoS Traffic Control Profiles (Priority Group Scheduling)
- Example: Configuring Traffic Control Profiles (Priority Group Scheduling)
- Understanding CoS Priority Group and Queue Guaranteed Minimum Bandwidth
- Example: Configuring Minimum Guaranteed Output Bandwidth
- Understanding CoS Priority Group Shaping and Queue Shaping (Maximum Bandwidth)
- Example: Configuring Maximum Output Bandwidth
- play_arrow Hierarchical Port Scheduling (ETS)
-
- play_arrow Data Center Bridging and Lossless FCoE
- play_arrow Data Center Bridging
- Understanding DCB Features and Requirements
- Understanding DCBX
- Configuring the DCBX Mode
- Configuring DCBX Autonegotiation
- Understanding DCBX Application Protocol TLV Exchange
- Defining an Application for DCBX Application Protocol TLV Exchange
- Configuring an Application Map for DCBX Application Protocol TLV Exchange
- Applying an Application Map to an Interface for DCBX Application Protocol TLV Exchange
- Example: Configuring DCBX Application Protocol TLV Exchange
- play_arrow Lossless FCoE
- Example: Configuring CoS PFC for FCoE Traffic
- Example: Configuring CoS for FCoE Transit Switch Traffic Across an MC-LAG
- Example: Configuring CoS Using ELS for FCoE Transit Switch Traffic Across an MC-LAG
- Example: Configuring Lossless FCoE Traffic When the Converged Ethernet Network Does Not Use IEEE 802.1p Priority 3 for FCoE Traffic (FCoE Transit Switch)
- Example: Configuring Two or More Lossless FCoE Priorities on the Same FCoE Transit Switch Interface
- Example: Configuring Two or More Lossless FCoE IEEE 802.1p Priorities on Different FCoE Transit Switch Interfaces
- Example: Configuring Lossless IEEE 802.1p Priorities on Ethernet Interfaces for Multiple Applications (FCoE and iSCSI)
- Troubleshooting Dropped FCoE Traffic
-
- play_arrow CoS Buffers and the Shared Buffer Pool
- play_arrow CoS Buffers Overview
- play_arrow Shared Buffer Pool Examples
- Example: Recommended Configuration of the Shared Buffer Pool for Networks with Mostly Best-Effort Unicast Traffic
- Example: Recommended Configuration of the Shared Buffer Pool for Networks with Mostly Best-Effort Traffic on Links with Ethernet PAUSE Enabled
- Example: Recommended Configuration of the Shared Buffer Pool for Networks with Mostly Multicast Traffic
- Example: Recommended Configuration of the Shared Buffer Pool for Networks with Mostly Lossless Traffic
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- play_arrow CoS on EVPN VXLANs
- play_arrow Configuration Statements and Operational Commands
Defining CoS Forwarding Classes
Forwarding classes allow you to group packets for transmission. The switch supports a total of eight (QFX10000 and NFX Series devices), 10 (QFX5200 switches), or 12 (other switches) forwarding classes. To forward traffic, you map (assign) the forwarding classes to output queues. Starting in Junos OS Release 22.1R1, QFX10000 Series devices support 16 forwarding classes.
The QFX10000 switches and NFX Series devices have eight output queues, queues 0 through 7. These queues support both unicast and multidestination traffic.
Except on QFX10000 and NFX Series devices, the switch has 10 output queues (QFX5200) or 12 output queues (other switches). Queues 0 through 7 are for unicast traffic and queues 8 through 11 are for multicast traffic. Forwarding classes mapped to unicast queues must carry unicast traffic, and forwarding classes mapped to multidestination queues must carry multidestination traffic. There are four default unicast forwarding classes and one default multidestination forwarding class.
The default forwarding classes, except on NFX Series devices, are:
Except on QFX10000, these are the default unicast forwarding classes.
best-effort
—Best-effort trafficfcoe
—Guaranteed delivery for Fibre Channel over Ethernet traffic (do not use on OCX Series switches)no-loss
—Guaranteed delivery for TCP no-loss traffic (do not use on OCX Series switches)network-control
—Network control traffic
QFX10002-60C does not support PFC and lossless queues; that is, default lossless queues (fcoe and no-loss) will be lossy queues.
The default multidestination forwarding class, except on QFX10000 switches and NFX Series devices, is:
mcast
—Multidestination traffic
The NFX Series devices have the following default forwarding classes:
best-effort (be)—Provides no service profile. Loss priority is typically not carried in a CoS value.
expedited-forwarding (ef)—Provides a low loss, low latency, low jitter, assured bandwidth, end-to-end service.
assured-forwarding (af)—Provides a group of values you can define and includes four subclasses: AF1, AF2, AF3, and AF4, each with two drop probabilities: low and high.
network-control (nc)—Supports protocol control and thus is typically high priority.
You can map forwarding classes to queues using the class
statement. You can map more than one forwarding class to a single queue. Except on QFX10000 or NFX Series devices, all forwarding classes mapped to a particular queue must be of the same type, either unicast or multicast. You cannot mix unicast and multicast forwarding classes on the same queue.
All of the forwarding classes mapped to the same queue must have the same packet drop attribute: either all of the forwarding classes must be lossy or all of the forwarding classes must be lossless. This is important because the default fcoe and no-loss forwarding classes have the no-loss
drop attribute, which is not supported on OCX Series switches. On OCX Series switches, do not map traffic to the default fcoe and no-loss forwarding classes.
[edit class-of-service forwarding-classes] user@switch# set class class-name queue-num queue-number <no-loss>
One example is to create a forwarding class named be2
and map it to queue 1:
[edit class-of-service forwarding-classes] user@switch# set class be2 queue-num 1
Another example is to create a lossless forwarding class named fcoe2
and map it to queue 5:
[edit class-of-service forwarding-classes] user@switch# set class fcoe2 queue-num 5 no-loss
On switches that do not run ELS software, if you are using Junos OS Release 12.2 or later, use the default forwarding-class-to-queue mapping for the lossless fcoe
and no-loss
forwarding classes. If you explicitly configure the lossless forwarding classes, the traffic mapped to those forwarding classes is treated as lossy (best-effort
) traffic and does not receive lossless treatment unless you include the optional no-loss
packet drop attribute introduced in Junos OS Release 12.3 in the forwarding class configuration..
On switches that do not run ELS software, Junos OS Release 11.3R1 and earlier supported an alternate method of mapping forwarding classes to queues that allowed you to map only one forwarding class to a queue using the statement:
[edit class-of-service forwarding-classes] user@switch# set queue queue-number class-name
The queue
statement has been deprecated and is no longer valid in Junos OS Release 11.3R2 and later. If you have a configuration that uses the queue
statement to map forwarding classes to queues, edit the configuration to replace the queue
statement with the class
statement.
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