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Example: Configure PFC Across L3 Interfaces
Priority-based flow control (PFC) helps ensure lossless transport across DCB interfaces by pausing incoming traffic when output queue buffers fill to a certain threshold. In addition to configuring PFC on L2 (bridging) interfaces, you can configure PFC on VLAN-tagged traffic that traverses L3 interfaces. This enables you to preserve the lossless characteristics that PFC provides on VLAN-tagged traffic, even when the traffic crosses L3 interfaces that connect two L2 networks.
This topic is applicable for VLAN-tagged traffic only. On supported platforms, you can also configure DSCP-based PFC for untagged traffic on L3 interfaces and L2 access interfaces. DSCP-based PFC uses a DSCP classifier to classify the traffic based on a 6-bit DSCP value that is mapped to a 3-bit PFC priority value. For details on configuring DSCP-based PFC on supporting switches, see Configuring DSCP-based PFC for Layer 3 Untagged Traffic.
Requirements
This example uses the following hardware and software components:
Two switches
Junos OS Release 13.2 or later for the QFX Series Switches
Two Ethernet hosts
Overview
On a network that uses two QFX Series switches to connect hosts on two different Ethernet networks across an L3 network, to configure PFC across the L2 and L3 interfaces, you must:
Configure the L2 and L3 interfaces on the switches
Configure VLANs to carry the traffic across the L2 and L3 networks
Configure integrated routing and bridging (IRB) interfaces on the L2 interfaces to move the L2 VLAN traffic to L3
Configure and apply the appropriate classifiers to the interfaces
Configure and apply CNPs on the interfaces to enable PFC on the traffic that you want to be lossless
Note:Configuring or changing PFC on an interface blocks the entire port until the PFC change is completed. After a PFC change is complete, the port is unblocked and traffic resumes. Blocking the port stops ingress and egress traffic, and causes packet loss on all queues on the port until the port is unblocked.
Configure lossless forwarding classes and either hierarchical port scheduling (also known as enhanced transmission selection) or direct port scheduling, depending on your switch, on the interfaces
PFC operates at the queue level, based on the IEEE 802.1p code point in the priority code point (PCP) field of the Ethernet frame header (sometimes known as the CoS bits). For this reason, VLAN-tagged traffic on L3 interfaces on which you want to enable PFC must use an IEEE 802.1p classifier to map incoming traffic to forwarding classes and loss priorities. You cannot use a DSCP or DSCP IPv6 classifier to classify L3 traffic if you want to enable PFC on VLAN-tagged traffic flows.
Topology
Figure 1 shows the topology for this example.
Table 1 shows the configuration components for this example. On the two switches, the Ethernet host-facing interfaces use the same interface names and configuration, and the Layer 3 network-facing interfaces use the same interface names and configuration.
Component |
Settings |
|---|---|
Hardware |
Two switches, Switch SW1 and Switch SW2.Two Ethernet hosts |
L3 interfaces (xe-0/0/40 and xe-0/0/41) and VLANs |
Interface xe-0/0/40:
Interface xe-0/0/41:
|
L2 interfaces (xe-0/0/20 and xe-0/0/21) and VLAN membership |
Family: Ethernet switchingInterface mode—trunkInterface xe-0/0/20 VLAN membership—vlan105Interface xe-0/0/21 VLAN membership—vlan106 |
VLANs for the IRB interfaces |
VLAN unit 105—family inet, IP address 100.105.1.1/24VLAN unit 106—family inet, IP address 100.106.1.1/24 |
L2 IRB interfaces |
Interface xe-0/0/20:
Interface xe-0/0/21:
|
Forwarding classes (both switches) |
Name—lossless-3Queue mapping—queue 3Packet drop attribute—no-loss Name—lossless-4Queue mapping—queue 4Packet drop attribute—no-loss Note:
Matching the forwarding class names (lossless-3 and lossless-4) to the queue number and to the classified IEEE 802.1p code point (priority) creates a configuration that is logical and easy to map because the forwarding class, queue, and priority all use the same number. Name—all-othersQueue mapping—queue 0Packet drop attribute—none Note:
The forwarding class all-others is for best-effort traffic that traverses the interfaces. |
L2 interface BA classifier |
Name—lossless-3-4-ieeeForwarding class lossless-3—mapped to code point 011 (IEEE 802.1p priority 3) and a PLP of lowForwarding class lossless-4—mapped to code point 100 (IEEE 802.1p priority 4) and a PLP of low Apply the L2 IEEE 802.1p classifier to both the L2 and the L3 interfaces (xe-0/0/20, xe-0/0/21, xe-0/040, and xe-0/0/41). |
CNP (PFC, both switches) |
Name—lossless-cnpPFC enabled on IEEE 802.1p code points—011 (lossless-3 forwarding class and priority), 100 (lossless-4 forwarding class and priority) Apply the CNP to both the L2 and the L3 interfaces (xe-0/0/20, xe-0/0/21, xe-0/040, and xe-0/0/41) to enable PFC on IEEE 802.1p code points 011 and 100. |
Enhanced transmission selection (ETS) hierarchical port scheduling (only if using ETS) |
Hierarchical port scheduling (ETS) includes configuring:
Hierarchical port scheduling also includes applying the hierarchical scheduler (defined in the TCP) to the interfaces. This example focuses on configuring PFC across the L2 and L3 interfaces. To maintain this focus, this example includes the CLI statements needed to configure hierarchical port scheduling, but does not include descriptive explanations of the configuration. The Related Documentation section provides links to example documents that show how to configure hierarchical port scheduling. Apply the scheduling configuration to both the L2 and the L3 interfaces (xe-0/0/20, xe-0/0/21, xe-0/040, and xe-0/0/41). |
Direct port scheduling (only if using port scheduling instead of ETS) |
Direct port scheduling includes configuring:
Port scheduling also includes applying the scheduler map to the interfaces. This example focuses on configuring PFC across the L2 and L3 interfaces. To maintain this focus, this example includes the CLI statements needed to configure direct port scheduling, but does not include descriptive explanations of the configuration. The Related Documentation section provides links to example documents that show how to configure port scheduling. Apply the scheduling configuration to both the L2 and the L3 interfaces (xe-0/0/20, xe-0/0/21, xe-0/040, and xe-0/0/41). |
Configuration
- CLI Quick Configuration
- Common Configuration (Applies to ETS Hierarchical Scheduling and to Port Scheduling)
- ETS Hierarchical Scheduling Configuration
- Port Scheduling Configuration
- Results
CLI Quick Configuration
To configure PFC across L3 interfaces, copy the following commands, paste them in a text file, remove the line breaks, change variables and details to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level. The same configuration applies to both Switch SW1 and Switch SW2. The configuration is separated into the configuration common to ETS and direct port scheduling, and the portions of the configuration that apply only to ETS and only to port scheduling.
Common Configuration (Applies to ETS Hierarchical Scheduling and to Port Scheduling)
set interfaces xe-0/0/40 vlan-tagging set interfaces xe-0/0/40 unit 0 vlan-id 103 set interfaces xe-0/0/40 unit 0 family inet address 100.103.1.2/24 set interfaces xe-0/0/41 vlan-tagging set interfaces xe-0/0/41 unit 0 vlan-id 104 set interfaces xe-0/0/41 unit 0 family inet address 100.104.1.2/24 set interfaces xe-0/0/20 unit 0 family ethernet-switching interface-mode trunk set interfaces xe-0/0/20 unit 0 family ethernet-switching vlan members vlan105 set interfaces xe-0/0/21 unit 0 family ethernet-switching interface-mode trunk set interfaces xe-0/0/21 unit 0 family ethernet-switching vlan members vlan106 set interfaces irb unit 105 family inet address 100.105.1.1/24 set interfaces irb unit 106 family inet address 100.106.1.1/24 set vlans vlan105 vlan-id 105 set vlans vlan106 vlan-id 106 set vlans vlan105 l3-interface irb.105 set vlans vlan106 l3-interface irb.106 set class-of-service forwarding-classes class lossless-3 queue-num 3 no-loss set class-of-service forwarding-classes class lossless-4 queue-num 4 no-loss set class-of-service forwarding-classes class all-others queue-num 0 set class-of-service classifiers ieee-802.1 lossless-3-4-ieee forwarding-class lossless-3 loss-priority low code-points 011 set class-of-service classifiers ieee-802.1 lossless-3-4-ieee forwarding-class lossless-4 loss-priority low code-points 100 set class-of-service congestion-notification-profile lossless-cnp input ieee-802.1 code-point 011 pfc set class-of-service congestion-notification-profile lossless-cnp input ieee-802.1 code-point 100 pfc set class-of-service schedulers lossless_sch transmit-rate 6g set class-of-service schedulers lossless_sch shaping-rate percent 100 set class-of-service schedulers all-others_sch transmit-rate 4g set class-of-service scheduler-maps lossless_map forwarding-class lossless-3 scheduler lossless_sch set class-of-service scheduler-maps lossless_map forwarding-class lossless-4 scheduler lossless_sch set class-of-service scheduler-maps all-others_map forwarding-class all-others scheduler all-others_sch set class-of-service interfaces xe-0/0/20 congestion-notification-profile lossless-cnp set class-of-service interfaces xe-0/0/20 unit 0 classifiers ieee-802.1 lossless-3-4-ieee set class-of-service interfaces xe-0/0/21 congestion-notification-profile lossless-cnp set class-of-service interfaces xe-0/0/21 unit 0 classifiers ieee-802.1 lossless-3-4-ieee set class-of-service interfaces xe-0/0/40 congestion-notification-profile lossless-cnp set class-of-service interfaces xe-0/0/40 classifiers ieee-802.1 lossless-3-4-ieee set class-of-service interfaces xe-0/0/41 congestion-notification-profile lossless-cnp set class-of-service interfaces xe-0/0/41 classifiers ieee-802.1 lossless-3-4-ieee
Configuration for ETS Hierarchical Scheduling
The ETS-specific portion of this example configures forwarding class set (priority group) membership and priority group CoS settings (TCP), and assigns the priority group and its CoS configuration to the interfaces.
set class-of-service forwarding-class-sets lossless_fc_set class lossless-3 set class-of-service forwarding-class-sets lossless_fc_set class lossless-4 set class-of-service forwarding-class-sets all-others_fc_set class all-others set class-of-service traffic-control-profiles lossless_tcp scheduler-map lossless_map set class-of-service traffic-control-profiles lossless_tcp guaranteed-rate percent 60 set class-of-service traffic-control-profiles lossless_tcp shaping-rate percent 100 set class-of-service traffic-control-profiles all-others_tcp scheduler-map all-others_map set class-of-service traffic-control-profiles all-others_tcp guaranteed-rate percent 40 set class-of-service interfaces xe-0/0/20 forwarding-class-set lossless_fc_set output-traffic-control-profile lossless_tcp set class-of-service interfaces xe-0/0/20 forwarding-class-set all-others_fc_set output-traffic-control-profile all-others_tcp set class-of-service interfaces xe-0/0/21 forwarding-class-set lossless_fc_set output-traffic-control-profile lossless_tcp set class-of-service interfaces xe-0/0/21 forwarding-class-set all-others_fc_set output-traffic-control-profile all-others_tcp set class-of-service interfaces xe-0/0/40 forwarding-class-set lossless_fc_set output-traffic-control-profile lossless_tcp set class-of-service interfaces xe-0/0/40 forwarding-class-set all-others_fc_set output-traffic-control-profile all-others_tcp set class-of-service interfaces xe-0/0/41 forwarding-class-set lossless_fc_set output-traffic-control-profile lossless_tcp set class-of-service interfaces xe-0/0/41 forwarding-class-set all-others_fc_set output-traffic-control-profile all-others_tcp
Configuration for Port Scheduling
The port-scheduling-specific portion of this example assigns the scheduler maps (which set the CoS treatment of the forwarding classes in the scheduler map) to the interfaces.
[edit class-of-service] set interfaces xe-0/0/20 scheduler-map lossless_map set interfaces xe-0/0/20 scheduler-map all-others_map set interfaces xe-0/0/21 scheduler-map lossless_map set interfaces xe-0/0/21 scheduler-map all-others_map set interfaces xe-0/0/40 scheduler-map lossless_map set interfaces xe-0/0/40 scheduler-map all-others_map set interfaces xe-0/0/41 scheduler-map lossless_map set interfaces xe-0/0/41 scheduler-map all-others_map
Common Configuration (Applies to ETS Hierarchical Scheduling and to Port Scheduling)
Step-by-Step Procedure
The following procedure shows you how to configure the VLANs, IRB interfaces, lossless forwarding classes, classifiers, PFC settings to enable PFC across L3 interfaces, and the queue scheduling configuration common to ETS and direct port scheduling. For completeness, the ETS hierarchical port scheduling and direct port scheduling configurations are included separately, in the following procedures, but without explanatory text. See the Related Documentation links for detailed examples of the scheduling elements of the configuration.
Configure the L3 interface VLANs and IP addresses:
[edit interfaces] user@switch# set xe-0/0/40 vlan-tagging user@switch# set xe-0/0/40 unit 0 vlan-id 103 user@switch# set xe-0/0/40 unit 0 family inet address 100.103.1.2/24 user@switch# set xe-0/0/41 vlan-tagging user@switch# set xe-0/0/41 unit 0 vlan-id 104 user@switch# set xe-0/0/41 unit 0 family inet address 100.104.1.2/24
Configure the L2 interface VLAN membership and interface mode:
[edit interfaces] user@switch# set xe-0/0/20 unit 0 family ethernet-switching interface-mode trunk user@switch# set xe-0/0/20 unit 0 family ethernet-switching vlan members vlan105 user@switch# set xe-0/0/21 unit 0 family ethernet-switching interface-mode trunk user@switch# set xe-0/0/21 unit 0 family ethernet-switching vlan members vlan106
Configure the IRB interfaces and VLANs to transport incoming L2 traffic assigned to VLANs vlan105 (of which interface xe-0/0/20 is a member) and vlan106 (of which interface xe-0/0/21 is a member) across L3:
[edit] user@switch# set interfaces irb unit 105 family inet address 100.105.1.1/24 user@switch# set interfaces irb unit 106 family inet address 100.106.1.1/24 user@switch# set vlans vlan105 vlan-id 105 user@switch# set vlans vlan106 vlan-id 106 user@switch# set vlans vlan105 l3-interface irb.105 user@switch# set vlans vlan106 l3-interface irb.106
Configure the lossless forwarding classes and a BE forwarding class for any other traffic that might use the interfaces:
[edit class-of-service] user@switch# set forwarding-classes class lossless-3 queue-num 3 no-loss user@switch# set forwarding-classes class lossless-4 queue-num 4 no-loss user@switch# set forwarding-classes class all-others queue-num 0
Configure the IEEE classifier for the L2 and L3 interfaces to classify incoming traffic into the lossless forwarding classes based on the IEEE 802.1p code point of the traffic:
[edit class-of-service classifiers] user@switch# set ieee-802.1 lossless-3-4-ieee forwarding-class lossless-3 loss-priority low code-points 011 user@switch# set ieee-802.1 lossless-3-4-ieee forwarding-class lossless-4 loss-priority low code-points 100
Configure the CNP to enable PFC on the lossless priorities (the lossless forwarding classes mapped to IEEE 802.1p code points 3 and 4):
[edit class-of-service congestion-notification-profile] user@switch# set lossless-cnp input ieee-802.1 code-point 011 pfc user@switch# set lossless-cnp input ieee-802.1 code-point 100 pfc
Apply the L2 IEEE 802.1p classifier and the CNP to the L3 interfaces:
[edit class-of-service interfaces] user@switch# set xe-0/0/40 classifiers ieee-802.1 lossless-3-4-ieee user@switch# set xe-0/0/40 congestion-notification-profile lossless-cnp user@switch# set xe-0/0/41 classifiers ieee-802.1 lossless-3-4-ieee user@switch# set xe-0/0/41 congestion-notification-profile lossless-cnp
Apply the L2 IEEE 802.1p classifier and the CNP to the L2 interfaces:
[edit class-of-service interfaces] user@switch# xe-0/0/20 unit 0 classifiers ieee-802.1 lossless-3-4-ieee user@switch# xe-0/0/20 congestion-notification-profile lossless-cnp user@switch# xe-0/0/21 unit 0 classifiers ieee-802.1 lossless-3-4-ieee user@switch# xe-0/0/21 congestion-notification-profile lossless-cnp
Configure queue scheduling to support the lossless configuration and map the schedulers to the forwarding classes:
[edit class-of-service] user@switch# set schedulers lossless_sch transmit-rate 6g user@switch# set schedulers lossless_sch shaping-rate percent 100 user@switch# set schedulers all-others_sch transmit-rate 4g user@switch# set scheduler-maps lossless_map forwarding-class lossless-3 scheduler lossless_sch user@switch# set scheduler-maps lossless_map forwarding-class lossless-4 scheduler lossless_sch user@switch# set scheduler-maps all-others_map forwarding-class all-others scheduler all-others_sch
ETS Hierarchical Scheduling Configuration
Step-by-Step Procedure
Configure hierarchical scheduling to support the lossless configuration and apply it to the L2 and L3 interfaces:
[edit class-of-service interfaces] user@switch# set forwarding-class-sets lossless_fc_set class lossless-3 user@switch# set forwarding-class-sets lossless_fc_set class lossless-4 user@switch# set forwarding-class-sets all-others_fc_set class all-others user@switch# set traffic-control-profiles lossless_tcp scheduler-map lossless_map user@switch# set traffic-control-profiles lossless_tcp guaranteed-rate percent 60 user@switch# set traffic-control-profiles lossless_tcp shaping-rate percent 100 user@switch# set traffic-control-profiles all-others_tcp scheduler-map all-others_map user@switch# set traffic-control-profiles all-others_tcp guaranteed-rate percent 40 user@switch# set interfaces xe-0/0/20 forwarding-class-set lossless_fc_set output-traffic-control-profile lossless_tcp user@switch# set interfaces xe-0/0/20 forwarding-class-set all-others_fc_set output-traffic-control-profile all-others_tcp user@switch# set interfaces xe-0/0/21 forwarding-class-set lossless_fc_set output-traffic-control-profile lossless_tcp user@switch# set interfaces xe-0/0/21 forwarding-class-set all-others_fc_set output-traffic-control-profile all-others_tcp user@switch# set interfaces xe-0/0/40 forwarding-class-set lossless_fc_set output-traffic-control-profile lossless_tcp user@switch# set interfaces xe-0/0/40 forwarding-class-set all-others_fc_set output-traffic-control-profile all-others_tcp user@switch# set interfaces xe-0/0/41 forwarding-class-set lossless_fc_set output-traffic-control-profile lossless_tcp user@switch# set interfaces xe-0/0/41 forwarding-class-set all-others_fc_set output-traffic-control-profile all-others_tcp
Port Scheduling Configuration
Step-by-Step Procedure
Apply port scheduling to support the lossless configuration on interfaces:
[edit class-of-service] user@switch# set interfaces xe-0/0/20 scheduler-map lossless_map user@switch# set interfaces xe-0/0/20 scheduler-map all-others_map user@switch# set interfaces xe-0/0/21 scheduler-map lossless_map user@switch# set interfaces xe-0/0/21 scheduler-map all-others_map user@switch# set interfaces xe-0/0/40 scheduler-map lossless_map user@switch# set interfaces xe-0/0/40 scheduler-map all-others_map user@switch# set interfaces xe-0/0/41 scheduler-map lossless_map user@switch# set interfaces xe-0/0/41 scheduler-map all-others_map
Results
Display the results of the interface, VLAN, and CoS configurations. The system shows only the explicitly configured parameters; it does not show default parameters. The results are valid for both Switch SW1 and Switch SW2 because the same configuration is used on both switches. The results are from the ETS hierarchical scheduling configuration, which show the more complex configuration. Direct port scheduling results would not show the TCP or forwarding class set portions of the configuration, but would display the name of the scheduler map under each interface. Other than that, the results are the same.
Display the results of the interface configuration:
user@switch# show configuration interfaces
xe-0/0/20 {
unit 0 {
family ethernet-switching {
interface-mode trunk;
vlan {
members vlan105;
}
}
}
}
xe-0/0/21 {
unit 0 {
family ethernet-switching {
interface-mode trunk;
vlan {
members vlan106;
}
}
}
}
xe-0/0/40 {
vlan-tagging;
unit 0 {
vlan-id 103;
family inet {
address 100.103.1.2/24;
}
}
}
xe-0/0/41 {
vlan-tagging;
unit 0 {
vlan-id 104;
family inet {
address 100.104.1.2/24;
}
}
}
irb {
unit 105 {
family inet {
address 100.105.1.1/24;
}
}
unit 106 {
family inet {
address 100.106.1.1/24;
}
}
}
vlan {
unit 105 {
family inet {
address 100.105.1.1/24;
}
}
unit 106 {
family inet {
address 100.106.1.1/24;
}
}
}Display the results of the vlan configuration:
user@switch# show configuration vlans
vlan105 {
vlan-id 105;
l3-interface irb.105;
}
vlan106 {
vlan-id 106;
l3-interface irb.106;
}Display the results of the CoS configuration:
user@switch# show configuration class-of-service
classifiers {
ieee-802.1 lossless-3-4-ieee {
forwarding-class lossless-3 {
loss-priority low code-points 011;
}
forwarding-class lossless-4 {
loss-priority low code-points 100;
}
}
}
forwarding-classes {
class lossless-3 queue-num 3 no-loss;
class lossless-4 queue-num 4 no-loss;
class all-others queue-num 0;
}
traffic-control-profiles {
lossless_tcp {
scheduler-map lossless_map;
shaping-rate percent 100;
guaranteed-rate percent 60;
}
all-others_tcp {
scheduler-map all-others_map;
guaranteed-rate percent 40;
}
}
forwarding-class-sets {
lossless_fc_set {
class lossless-3;
class lossless-4;
}
all-others_fc_set {
class all-others;
}
}
congestion-notification-profile {
lossless-cnp {
input {
ieee-802.1 {
code-point 011 {
pfc;
}
code-point 100 {
pfc;
}
}
}
}
}
interfaces {
xe-0/0/20 {
forwarding-class-set {
lossless_fc_set {
output-traffic-control-profile lossless_tcp;
}
all-others_fc_set {
output-traffic-control-profile all-others_tcp;
}
}
congestion-notification-profile lossless-cnp;
unit 0 {
classifiers {
ieee-802.1 lossless-3-4-ieee;
}
}
}
xe-0/0/21 {
forwarding-class-set {
all-others_fc_set {
output-traffic-control-profile all-others_tcp;
}
lossless_fc_set {
output-traffic-control-profile lossless_tcp;
}
}
congestion-notification-profile lossless-cnp;
unit 0 {
classifiers {
ieee-802.1 lossless-3-4-ieee;
}
}
}
xe-0/0/40 {
forwarding-class-set {
lossless_fc_set {
output-traffic-control-profile lossless_tcp;
}
all-others_fc_set {
output-traffic-control-profile all-others_tcp;
}
}
congestion-notification-profile lossless-cnp;
classifiers {
ieee-802.1 lossless-3-4-ieee;
}
}
xe-0/0/41 {
forwarding-class-set {
lossless_fc_set {
output-traffic-control-profile lossless_tcp;
}
all-others_fc_set {
output-traffic-control-profile all-others_tcp;
}
}
congestion-notification-profile lossless-cnp;
classifiers {
ieee-802.1 lossless-3-4-ieee;
}
}
}
scheduler-maps {
lossless_map {
forwarding-class lossless-3 scheduler lossless_sch;
forwarding-class lossless-4 scheduler lossless_sch;
}
all-others_map {
forwarding-class all-others scheduler all-others_sch;
}
}
schedulers {
lossless_sch {
transmit-rate 6g;
shaping-rate percent 100;
}
all-others_sch {
transmit-rate 4g;
}
}
To quickly configure the switch, issue the load merge
terminal command, and then copy the hierarchies and paste them
into the switch terminal window.
Verification
To verify that the PFC across L3 interfaces configuration has been created and is operating properly, perform these tasks:
- Verifying the Interface Configuration
- Verifying the VLAN Configuration
- Verifying the PFC Configuration (CNP)
- Verify the Forwarding Class Configuration
- Verifying the Classifier Configuration
- Verifying the Interface CoS Configuration (Hierarchical Scheduling, PFC, and Classifier Mapping to Interfaces)
Verifying the Interface Configuration
Purpose
Verify that the L2 Ethernet interfaces, L3 IP interfaces, IRB interfaces, and VLAN interfaces have been created on the switch and are correctly configured.
Action
Display the switch interface configuration using the show configuration interfaces command:
user@switch> show configuration interfaces
xe-0/0/20 {
unit 0 {
family ethernet-switching {
interface-mode trunk;
vlan {
members vlan105;
}
}
}
}
xe-0/0/21 {
unit 0 {
family ethernet-switching {
interface-mode trunk;
vlan {
members vlan106;
}
}
}
}
xe-0/0/40 {
vlan-tagging;
unit 0 {
vlan-id 103;
family inet {
address 100.103.1.2/24;
}
}
}
xe-0/0/41 {
vlan-tagging;
unit 0 {
vlan-id 104;
family inet {
address 100.104.1.2/24;
}
}
}
irb {
unit 105 {
family inet {
address 100.105.1.1/24;
}
}
unit 106 {
family inet {
address 100.106.1.1/24;
}
}
}
vlan {
unit 105 {
family inet {
address 100.105.1.1/24;
}
}
unit 106 {
family inet {
address 100.106.1.1/24;
}
}
}Meaning
The show configuration interfaces command
displays all of the interfaces configured on the switch. The command
output shows that:
Interfaces xe-0/0/20 and xe-0/0/21 are Ethernet interfaces (family ethernet-switching) in trunk interface mode. Interface xe-0/0/20 is a member of VLAN vlan105, and interface xe-0/0/21 is a member of VLAN vlan106.
Interfaces xe-0/0/40 and xe-0/0/41 are IP interfaces (family inet) with VLAN tagging enabled. Interface xe-0/0/40 has an IP address of 100.103.1.2/24 and a VLAN ID of 103. Interface xe-0/0/41 has an IP address of 100.104.1.2/24 and a VLAN ID of 104.
Two IRB interfaces are configured, IRB unit 105 with an IP address of 100.105.1.1/24 and IRB unit 106 with an IP address of 100.106.1.1/24.
Two VLAN interfaces are configured: VLAN unit 105 with an IP address of 100.105.1.1/24 (for IRB interface unit 105) and VLAN unit 106 with an IP address of 100.106.1.1/24 (for IRB interface unit 106).
Verifying the VLAN Configuration
Purpose
Verify that VLANs have been created on the switch and are correctly configured.
Action
Display the VLAN configuration using the show configuration
vlans command:
user@switch> show configuration vlans
vlan105 {
vlan-id 105;
l3-interface irb.105;
}
vlan106 {
vlan-id 106;
l3-interface irb.106;
}Meaning
The show configuration vlans command displays
all of the VLANs configured on the switch. The command output shows
that:
VLAN vlan105 has been configured with VLAN ID 105 on IRB interface irb.105.
VLAN vlan106 has been configured with VLAN ID 106 on IRB interface irb.106.
Verifying the PFC Configuration (CNP)
Purpose
Verify that PFC has been enabled on the correct IEEE 802.1p code points (priorities) in the CNP.
Action
Display the PFC configuration using the show configuration
class-of-service congestion-notification-profile command:
user@switch> show configuration class-of-service congestion-notification-profile
lossless-cnp {
input {
ieee-802.1 {
code-point 011 {
pfc;
}
code-point 100 {
pfc;
}
}
}
}
Meaning
The show configuration class-of-service congestion-notification-profile command displays all of the CNPs configured on the switch. The command
output shows that:
The CNP named
lossless-cnpis configured on the switch.The CNP
lossless-cnpenables PFC on IEEE 802.1p code points 100 and 100.
Verify the Forwarding Class Configuration
Purpose
Verify that the two lossless forwarding classes and the BE forwarding class have been configured on the switch.
Action
Display the forwarding class configuration using the show configuration class-of-service forwarding-classes command:
user@switch> show configuration class-of-service forwarding-classes class lossless-3 queue-num 3 no-loss; class lossless-4 queue-num 4 no-loss; class all-others queue-num 0;
Meaning
The show configuration class-of-service forwarding-classes command displays all
of the forwarding classes configured on the switch. Default forwarding
classes are not displayed. The command output shows that:
Forwarding class
lossless-3is mapped to queue 3 and is configured as a lossless forwarding class (theno-lossattribute is applied)Forwarding class
lossless-4is mapped to queue 4 and is configured as a lossless forwarding class (theno-lossattribute is applied)Forwarding class
all-othersis mapped to queue 0. It is not a lossless forwarding class (theno-lossattribute is not applied).
Verifying the Classifier Configuration
Purpose
Verify that the IEEE 802.1p classifier has been configured on the switch.
Action
Display the classifier configuration using the show configuration class-of-service classifiers command:
user@switch> show configuration class-of-service classifiers
ieee-802.1 lossless-3-4-ieee {
forwarding-class lossless-3 {
loss-priority low code-points 011;
}
forwarding-class lossless-4 {
loss-priority low code-points 100;
}
}
Meaning
The show configuration class-of-service classifiers command displays all of the
classifiers configured on the switch. The command output shows that the L2
IEEE 802.1p classifier lossless-3-4-ieee classifies traffic
with the code point 011 into the lossless-3 forwarding
class with a loss priority of low, and classifies traffic
with the code point 100 into the lossless-4 forwarding
class with a loss priority of low.
Verifying the Interface CoS Configuration (Hierarchical Scheduling, PFC, and Classifier Mapping to Interfaces)
Purpose
Verify that the interfaces have the correct hierarchical scheduling, PFC, and classifier configurations.
The results are from the ETS hierarchical scheduling configuration, which shows the more complex configuration. Direct port scheduling results do not show the TCP or forwarding class set portions of the interface configuration, but rather display the name of the scheduler map under each interface.
Action
Display the interface CoS configuration using the show configuration class-of-service interfaces command:
user@switch> show configuration class-of-service interfaces
xe-0/0/20 {
forwarding-class-set {
lossless_fc_set {
output-traffic-control-profile lossless_tcp;
}
all-others_fc_set {
output-traffic-control-profile all-others_tcp;
}
}
congestion-notification-profile lossless-cnp;
unit 0 {
classifiers {
ieee-802.1 lossless-3-4-ieee;
}
}
}
xe-0/0/21 {
forwarding-class-set {
all-others_fc_set {
output-traffic-control-profile all-others_tcp;
}
lossless_fc_set {
output-traffic-control-profile lossless_tcp;
}
}
congestion-notification-profile lossless-cnp;
unit 0 {
classifiers {
ieee-802.1 lossless-3-4-ieee;
}
}
}
xe-0/0/40 {
forwarding-class-set {
lossless_fc_set {
output-traffic-control-profile lossless_tcp;
}
all-others_fc_set {
output-traffic-control-profile all-others_tcp;
}
}
congestion-notification-profile lossless-cnp;
classifiers {
ieee-802.1 lossless-3-4-ieee;
}
}
xe-0/0/41 {
forwarding-class-set {
lossless_fc_set {
output-traffic-control-profile lossless_tcp;
}
all-others_fc_set {
output-traffic-control-profile all-others_tcp;
}
}
congestion-notification-profile lossless-cnp;
classifiers {
ieee-802.1 lossless-3-4-ieee;
}
}
Meaning
The show configuration class-of-service interfaces command displays all of the CoS components configured on the switch
interfaces. The command output shows that:
The configuration on L2 Ethernet interfaces xe-0/0/20 and xe-0/0/21 includes:
Hierarchical scheduling—The forwarding class set
lossless_fc_setwith the TCPlossless_tcpfor the lossless traffic, and the forwarding class setall-others_fc_setwith the TCPall-others_tcpfor the best-effort traffic are applied to both interfaces.PFC—The
lossless-cnpCNP is applied to both interfaces.Classifiers—The L2 IEEE 802.1p classifier
lossless-3-4-ieeeis applied to both interfaces.
The configuration on L3 IP interfaces xe-0/0/40 and xe-0/0/41 includes:
Hierarchical scheduling—The forwarding class set
lossless_fc_setwith the TCPlossless_tcpfor the lossless traffic, and the forwarding class setall-others_fc_setwith the TCPall-others_tcpfor the best-effort traffic are applied to both interfaces.PFC—The
lossless-cnpCNP is applied to both interfaces.Classifiers—The L2 IEEE 802.1p classifier
lossless-3-4-ieeeis applied to both interfaces. Traffic that would use a DSCP or a DSCP IPv6 classifier if it were configured uses the IEEE 802.1p classifier instead. Using the IEEE 802.1p classifier allows the interface to use PFC to pause traffic during periods of congestion to prevent packet loss.