Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

Announcement: Try the Ask AI chatbot for answers to your technical questions about Juniper products and solutions.

close
header-navigation

Solutions

Featured solutions AI Campus and branch Data center WAN Security Service provider Cloud operator Industries
Campus and Branch

Welcome to the NOW Way to Wi-Fi

Take your networking performance to new heights with a modern, cloud-native, AI-Native architecture. Only Juniper can help you unleash the full potential of Wi-Fi 7 with our AI-Native platform for innovation.
Prepare for liftoff
Business intelligence analyst dashboard on virtual screen. Big data Graphs Charts.

AI Data Center Networking

Juniper’s AI data center solution is a quick way to deploy high performing AI training and inference networks that are the most flexible to design and easiest to manage with limited IT resources.
Find out more
Enterprise AI-Native Networking

Enterprise AI‑Native Routing

Juniper's Ai-Native routing solution delivers robust 400GbE and 800GbE capabilities for unmatched performance, reliability, and sustainability at scale.
Explore enterprise routing
Zero trust security

Ops4AI Lab

Visit our lab in Sunnyvale, CA and see our AI data center solution for yourself. You can try out your own model’s functionality and performance, too.
Visit the lab
Enterprise AI-Native Networking

Enterprise AI‑Native Routing

Juniper's Ai-Native routing solution delivers robust 400GbE and 800GbE capabilities for unmatched performance, reliability, and sustainability at scale.
Explore enterprise routing
Higher Education

Shaping Student Experiences: The NOW Way to Build Higher Education Networks

Juniper Networks CIO Sharon Mandell and a virtual summit of C-level IT leaders from prestigious institutions discuss ongoing efforts to support digital transformation on campus.
Watch now
Hand on tablet with healthcare overlay of graphics

Security in healthcare

In this IDC Spotlight report, discover how AI networking can automate and strengthen a healthcare ecosystem to defeat criminals and prevent loss. 
Gain insights into ecosystem security
Retail

The Future of In-Store Technologies

Retail experts Kevin McCartan, Senior IT Service Delivery Engineer at Musgrave; Jack Stratten of Insider Trends; and Christian Gilby, Senior Director of Product Marketing at Juniper Networks, discuss customer experiences.
See the future

Products

Wireless access Wired access SD-WAN / SASE Routing and switching Security Mist AI™ Management software Network operating system Blueprint for AI-Native Acceleration Optics
  • Operations
ACX7020 router

Juniper ACX7020 Cloud Metro Access Router

Legacy networks simply cannot meet the demands of today’s rapidly evolving metro landscape. Unlock a new generation of highly scalable architectures and automated operations with the Juniper ACX7020. 
Learn more
EX4000 Ethernet Switch

Next-gen AI-Native EX4000 line of switches

Lack of AI innovation from your current networking vendor slowing you down? Embrace Juniper’s cloud-native, AI-Native access switches that support every level and layer, across nearly every deployment.
Discover how
The Q and AI text with an image of Bob Friday and Kedar Dhuru.

The Q&AI Podcast

Delivering practical solutions and enriching discussions, this podcast series is a vital resource for those seeking an in-depth exploration of AI's transformative potential.
Catch the latest episode

Services

Services
Services AI Care

Juniper AI Care Services Revolutionize Your Service Experience

Our industry-first AI-Native services couple AIOps with our deep expertise across the full network life cycle. You can move from reactive response to proactive insight and action.
Explore AI Care Services
Services AI Data Center

Juniper AI Data Center Deployment Services Optimize Your AI Model Runs

We use our expertise and validated designs to help design, deploy, validate and tune networks, including GPUs and storage, to get the most from your AI infrastructure operation.
Learn about AI Data Center Deployment Services

Partners

Partners

Support and Documentation

Support and Documentation

Learn

About Juniper Training Events The Feed Resources Technology learning topics Thought leadership and insights
Audience raising hands up while businessman is speaking in training at the office.

Juniper certification and training news

See the latest
Ringing of the bell

All global events

See the latest
AI-native-now

AI-Native NOW event series

Explore events
AINN AI Innovation Impact Virtual Event

AI-Native NOW: AI Innovation and Impact

Register NOW
Juniper's Christina Hendrix at the head of a conference table. With the text "The NOW Way to Network" overlayed, with "NOW" emphasizing the "O" in green color.

The NOW Way to Network

Watch the video series
AI Native Now

Executive insights

Dive deep with leading experts and thought leaders on all the topics that matter most to your business, from AI to network security to driving rapid, relevant transformation for your business.
Learn more
A keynote speaker giving a presentation at a conference. There are dozens of people sitting around them. The presentation is displayed via projector on all the walls in the room.

Leadership voices

Juniper Networks’ leaders operate on the front lines of creating the network of the future. Take a look around to see what’s on their minds.
Watch now
Bob Friday and Jessica Garrison speaking

Bob Friday Talks

Join Bob as he ventures into all the knowns -- and -- unknowns -- of AI.
Catch the latest episode
Documentation
Menu
License Guide
Quick Starts
Validated Designs
Explore Pathfinder Apps
CLI Explorer
Feature Explorer
Hardware Compatibility Tool
Port Checker
Browse All
Collapse

Pathfinder Apps

All

By Software

By Hardware

Learn More
Pathfinder HomeCLI ExplorerCompliance AdvisorFeature ExplorerHardware Compatibility ToolJunos XML API ExplorerJunos YANG Data Model ExplorerPort CheckerPower CalculatorSNMP MIB ExplorerSystem Log Explorer
CLI ExplorerFeature ExplorerJunos XML API ExplorerJunos YANG Data Model ExplorerSNMP MIB ExplorerSystem Log Explorer
Compliance AdvisorFeature ExplorerHardware Compatibility ToolPort CheckerPower Calculator
Home Documentation Junos OS Release Notes: Junos OS Release 21.4R1 Junos OS Release Notes for PTX Series What's New What's New in 21.4R1

Release Notes: Junos OS Release 21.4R1

Junos OS Junos OS Evolved
keyboard_arrow_up
close
keyboard_arrow_left
Release Notes: Junos OS Release 21.4R1
Table of Contents Expand all
list Table of Contents
file_download PDF
{ "lLangCode": "en", "lName": "English", "lCountryCode": "us", "transcode": "en_US" }
English
keyboard_arrow_right

Class of Service

date_range 16-Dec-21
arrow_backward
arrow_forward
  • Support for ToS/DSCP rewrite option protocol (PTX and QFX)—Starting in Junos OS Release 21.4R1, you can mark IP ToS bits when IP packets enter MPLS tunnel during MPLS push events, by enabling the CoS rewrite feature 'protocol mpls' in your PTX Series and QFX Series devices. By enabling this configuration, you ensure that dedicated Internet access (DIA) traffic is not treated with QoS across the core of the network.
  • [See Routing Policies, Firewall Filters, and Traffic Policers]
  • Support for CoS in EVPN-VXLAN topology (QFX5210)—Starting in Junos OS Release 21.4R1, you can configure CoS on a QFX5210 L3 VXLAN gateway in an EVPN-VXLAN fabric. However, this configuration presents a few limitations:
    • For uniform packet classification within the system, both the access port and the loopback port must have the same behavior aggregate (BA) or fixed classifier.
    • If traffic from multiple access port converges on the same loopback port and if some of the access-port traffic needs a different classification, then you must apply a multifield classifier on the loopback port for the traffic of interest.
    • PFC (both IEEE and DSCP based) is not supported as PFC backpressure will not reach the access port from network port due to the loopback port design.
    • If you need a classifier on the network port (DSCP), you must have the same classifier on the network, loopback, and access ports, as network-to-access traffic also goes through the same loopback port.
    • Other general VxLAN CoS limitations applicable for all QFX5000 switches apply to the QFX5210.
    [See Understanding CoS on OVSDB-Managed VXLAN Interfaces and CoS Support on EVPN VXLANs]
arrow_backward PREVIOUS Hardware
NEXT arrow_forward MPLS
footer-navigation

© 1999 - 2025 Juniper Networks, Inc. All rights reserved.

Scroll to top