- play_arrow Weighted Random Early Detection (WRED) and Explicit Congestion Notification (ECN)
- play_arrow WRED and Drop Profiles
- play_arrow Explicit Congestion Notification (ECN)
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- 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)
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- 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
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- 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
Troubleshooting an Unexpected Rewrite Value
Problem
Description
Traffic from one or more forwarding classes on an egress port is assigned an unexpected rewrite value.
For packets that carry both an inner VLAN tag and an outer VLAN tag, the rewrite rules rewrite only the outer VLAN tag.
Cause
If you configure a rewrite rule for a forwarding class on an egress port, but you do not configure a rewrite rule for every forwarding class on that egress port, then the forwarding classes that do not have a configured rewrite rule are assigned random rewrite values.
For example:
Configure forwarding classes
fc1,fc2, andfc3.Configure rewrite rules for forwarding classes
fc1andfc2, but not for forwarding classfc3.Assign forwarding classes
fc1,fc2, andfc3to a port.
When traffic for these forwarding classes flows through the port, traffic for forwarding classes fc1 and fc2 is rewritten correctly. However, traffic for forwarding class fc3 is assigned a random rewrite value.
Solution
If any forwarding class on an egress port has a configured rewrite rule, then all forwarding classes on that egress port must have a configured rewrite rule. Configuring a rewrite rule for any forwarding class that is assigned a random rewrite value solves the problem.
If you want the forwarding class to use the same code point value assigned to it by the ingress classifier, specify that value as the rewrite rule value. For example, if a forwarding class has the IEEE 802.1 ingress classifier code point value 011, configure a rewrite rule for that forwarding class that uses the IEEE 802.1p code point value 011.
There are no default rewrite rules. You can bind one rewrite rule for DSCP traffic and one rewrite rule for IEEE 802.1p traffic to an interface. A rewrite rule can contain multiple forwarding-class-to-rewrite-value mappings.
To assign a rewrite value to a forwarding class, add the new rewrite value to the same rewrite rule as the other forwarding classes on the port:
content_copy zoom_out_map[edit class-of-service rewrite-rules] user@switch# set (dscp | ieee-802.1) rewrite-name forwarding-class class-name loss-priority priority code-point (alias | bits)
For example, if the other forwarding classes on the port use rewrite values defined in the rewrite rule
custom-rw, the forwarding classbe2is being randomly rewritten, and you want to use IEEE 802.1 code point002for thebe2forwarding class:content_copy zoom_out_map[edit class-of-service rewrite-rules] user@switch# set ieee-802.1 custom-rw forwarding-class be2 loss-priority low code-point 002
Enable the rewrite rule on an interface if it is not already enabled on the desired interface:
content_copy zoom_out_map[edit] user@switch# set class-of-service interfaces interface-name unit unit rewrite-rules (dscp | ieee-802.1) rewrite-rule-name
For example, to enable the rewrite rule
custom-rwon interfacexe-0/0/24.0:content_copy zoom_out_map[edit] user@switch# set class-of-service interfaces xe-0/0/24 unit 0 rewrite-rules ieee-802.1 custom-rw
