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Junos OS Evolved Release Notes for QFX5220 Switches


These release notes accompany Junos OS Evolved Release 19.3R1 for QFX5220-32CD and QFX5220-128C Switches. They describe new and changed features, limitations, and known and resolved problems in the hardware and software.

What’s New

What’s New in Junos OS Evolved Release 19.3R2

There are no new or changed features in Junos OS Evolved Release 19.3R2 for the QFX5220.

What’s New in Junos OS Evolved Release 19.3R1

Learn about new features introduced in Junos OS Evolved Release 19.3R1 for the QFX5220.

Class of Service

  • Support for QMON per-port-buffer monitoring with QFX5220 devices—Starting in Junos OS Evolved Release 19.3R1, Junos OS Evolved supports per-port-buffer monitoring with QFX 5220 routers.

    [See Understanding Class of Service.]

Dynamic Host Configuration Protocol

  • DHCPv4 and DHCPv6 Stateless Relay (QFX5220 switches)—Starting in Junos OS Evovled Release 19.3R1, DHCPv4 and DHCPv6 stateless relay is supported on QFX5220 switches.

    [See DHCP for Switches.]

Interfaces and Chassis

  • Support for 400-Gigabit Ethernet Active Optic Cable (AOC) (QFX5220-32CD)—Starting in Junos Evolved Release 19.3R1, these optical cables are now supported:

    • QSFP56-DD-400G-AOC-1M

    • QSFP56-DD-400G-AOC-3M

    • QSFP56-DD-400G-AOC-5M

    • QSFP56-DD-400G-AOC-7M

    • QSFP56-DD-400G-AOC-10M

    • QSFP56-DD-400G-AOC-15M

    • QSFP56-DD-400G-AOC-20M

    • QSFP56-DD-400G-AOC-30M

    [See QFX5220-32CD Port Panel.]

  • Resilient hashing support for equal-cost multipath routes (QFX5220 switches)—Starting with Junos OS Evolved Release 19.3R1, equal-cost multipath (ECMP) supports resilient hashing on QFX5220 switches. An ECMP group for a route contains multiple next-hop equal cost addresses for the same destination in the routing table. Junos OS evolved uses a hash algorithm to choose one of the next-hop addresses in the ECMP group to install in the forwarding table. Flows to the destination are rebalanced using CLI-based hashing. Resilient hashing enhances ECMPs by minimizing destination remapping when a member is deleted from the ECMP group.

    Currently, only resilient hashing on ECMP is supported.


    The QFX5220 does not support the hash field no-incoming-device.

    [See Resilient Hashing on ECMP and ecmp-resilient-hash.]

Junos Telemetry Interface

  • JTI support for interface burst monitoring (QFX5220-128C and QFX5220-32CD)—Junos OS Evolved Release 19.3R1 supports interface burst monitoring on Junos telemetry interface (JTI) to monitor physical interfaces for bursts. Use interface burst monitoring to help troubleshoot problems, make decisions, and adjust resources as needed.

    Exported statistics report:

    • Peak byte rate in milliseconds

    • The time peak bytes are detected (for both receive and transmit directions)

    You can export interface burst statistics from the Juniper device to an outside collector by including the sensor /junos/system/linecard/bmon-sw/ in a subscription using remote procedure call (gRPC) services.

    To provision the sensor to export data through gRPC services, use the telemetrySubcribe RPC to specify telemetry parameters. Streaming telemetry data through gRPC also requires the OpenConfig for Junos OS module.


    This feature does not detect microbursts.

    [See Understanding OpenConfig and gRPC on Junos Telemetry Interface and Guidelines for gRPC Sensors (Junos Telemetry Interface).]

Juniper Extension Toolkit APIs

  • Configure firewall configurations programmatically (QFX5220)—Server stubs generated by JAPI file are made available for third-party applications using firewall configurations.

    [See ENGNET.]

Layer 2 Protocols

  • Spanning Tree Protocol (STP), Rapid Spanning Tree Protocol (RSTP), Multiple Spanning Tree Protocol (MSTP), and VLAN Spanning Tree Protocol (VSTP) support (QFX5220 switch)—Starting in Junos OS Evolved Release 19.3R1, you can enable these protocols to have a switch advertise its identity and capabilities on a LAN and receive information about other network devices.

    [See Overview of Spanning Tree Protocols.]

Network Management and Monitoring

  • sFlow support—sFlow is a monitoring technology for high-speed switched or routed networks. An sFlow monitoring system consists of an sFlow agent embedded in the router and a monitoring station called a collector. sFlow randomly samples network packets and sends the samples as UDP datagrams to the IP address and UDP destination port of the collector.

    [See Understanding How to Use sFlow Technology for Network Monitoring.]

Routing Policy and Firewall Filters

  • CLI support for firewall family ethernet-switching filter configuration (QFX5220)—CLI support is added for set firewall family ethernet-switching filter <filter-name> term <term-name> from source-port-match-optimize <port> and set firewall family ethernet-switching filter <filter-name> term <term-name> from destination-port-match-optimize <port>.

Software Installation and Upgrade

  • Zero touch provisioning using WAN interfaces (QFX5220-128C)—Starting in Junos OS Evolved Release 19.3R1, in Zero Touch Provisioning (ZTP), you can use either WAN interfaces or management interfaces, to automatically download and install the appropriate software and the configuration file on your device during the bootstrap process.

    ZTP automatically configures on WAN port that has default port speed of 100-Gbps, and then connects your device to the Dynamic Host Configuration Protocol (DHCP) server to perform the bootstrap process:

    • If multiple DHCP replies arrive, the ZTP choose the best set of arguments.

    • If multiple interfaces provpide the same arguments, ZTP choose one of the equal interfaces.

    • If there is an error while connecting to DHCP server, ZTP retry to connect DHCP server, and if multiple interfaces again provide same arguments, ZTP choose one of the interfaces.

    We recommend you to provision the DHCP server, which specifies the best set of arguments, and save the software and configuration file in the specified DHCP server path on the file server.

    [See Zero Touch Provisioning.]

Timing and Synchronization

  • NTP over WAN ports (QFX5220)—Starting with Junos OS Evolved Release 19.3R1, QFX5220 switches support NTP over WAN ports.

    [See NTP Overview.]

What’s Changed

What’s Changed in Junos OS Evolved Release 19.3R2

There are no changes in syntax or behavior in Junos OS Evolved Release 19.3R2 for the QFX5220.

What’s Changed in Junos OS Evolved Release 19.3R1

Learn about what changed in Junos OS Evolved Release 19.3R1 for the QFX5220.

Changes in CLI Statements and Commands

  • To see the list of CLI statements and commands changed in Junos OS Evolved, see How Junos OS Evolved Differs from Junos OS in the Introducing Junos Os Evolved Guide.

Software-Defined Network

  • Increase in the maximum value of delegation-cleanup-timeout (QFX Series)—You can now configure a maximum of 2147483647 seconds as the delegation cleanup time for a Path Computation Client (PCC). This extends the time taken by the PCC to retain the last provided path over a PCEP session from the last session down time.

    With the increase in maximum value of delegation-cleanup-timeout from 600 to 2147483647 seconds, you can benefit during a Path Computation Element (PCE) failover, or other network issues that may disrupt the PCEP session with the main active stateful PCE.

    [See delegation-cleanup-timeout.]

Known Limitations

Learn about limitations in this release for the QFX5220. For the most complete and latest information about known Junos OS Evolved defects, use the Juniper Networks online Junos Problem Report Search application.

Class of Service (CoS)

  • In QFX-5220 for multicast service pool only entry based threshold (MCQE) only used for accounting. This is different from existing platforms, where both cell based & entry based thresholds are used for accounting. In QFX-5220 we have 13600 multicast queue entries (MCQE) per ITM (total 27200). Peak buffer occupancy in multicast service pool will be based on this value. PR1457707

System Management

  • Junos OS Evolved uses the request system shutdown (reboot | power-off | halt) commands. This is different than the Junos commands for same functionality.

  • It takes up to 420s in QFX5220-128C for interfaces to come up after reboot when all ports are channelized. The higher time is due to the time taken to download firmware to all 64 dies PR1433083

Open Issues

Learn about open issues in this release for the QFX5220. For the most complete and latest information about known Junos OS Evolved defects, use the Juniper Networks online Junos Problem Report Search application.


  • The following XML tags are missing in Junos OS Evolved for the show route forwarding-table CLI: <address-family>, <enabled-protocols>, <to> PR1429413

Interfaces and Chassis

  • QFX5200 running Junos OS Evolved: IFD stats retain old values after clear stats & deactivate/activate on interface where MTU was configured. Workaround is to run clear interfaces statistics once after deactivate/activate interface (for which MTU is configured). PR1403606

  • When exposed to traffic with packet sizes greater than the interface MTU and the do-not-fragment bit set, the traffic will be dropped as expected however the "Output MTU Error" counter does not increase when issuing a "show interfaces extensive" command. PR1434860

  • Two ifd flaps will be observed for each ifd if mtu or lacp config is changed. The flaps maybe observed upto 15mins apart if the channelized configuration is present and mtu is applied for all 128 interfaces. PR1446214

  • After a link flap, a 400G link may take up to 50 seconds before returning stably to "up". PR1450606

Routing Protocols

  • In 19.3R2 BFD sessions might flap for brief period of time after configuration commit which involves new IFD creation/deletion (for ex. AE creation/deletion). Here BFD packets are dropped for brief period due to traffic block and unblock from COS module during IFD creation/deletion time. Issue is fixed in next release. PR1473327

System Management

  • When removing and inserting a 400G AOC module there can be up to 90 seconds delay before the link establishes after insertion. PR1454259

  • With LACP configurations present some of the channelised interfaces remain down after a reboot. PR1459554

  • After committing the IPCLOS scaled profile configuration with 32 ports or software image upgrade, some DAC interfaces may remain down. Workaround: Reboot the switch with the saved IPCLOS configuration. PR1460442

User Interface and Configuration

  • Restart of App cmdd is failing with below error: error: abnormal communication termination with command-handler daemon error: the command-handler subsystem is not responding to management requests PR1434409

Resolved Issues

Learn which issues were resolved in Junos OS Evolved Release 19.3R2 for the QFX5220.

For the most complete and latest information about known Junos OS Evolved defects, use the Juniper online Junos Problem Report Search application.

Dynamic Host Configuration Protocol

  • In certain configurations DHCPv6 client fails to bind over L2 LDRA-connected DHCPv6 Relay. PR1458040

  • Currently when multiple syslog servers are configured on the DHCP server, only the latest syslog server that is set will be accepted and configured for remote logging on the server. PR1458931

Layer 2 Features

  • The show ethernet-switch statistics command is not supported in Junos OS Evolved 19.3R1. Previous releases. In Junos OS Evolved 19.2R1, this command is used to display "Current Mac count". PR1457307

Interfaces and Chassis

  • SNMP queries via the entPhysicalTable MIB will not display transceiver/optics data. PR1414503

  • Intermittently one or more channelized interfaces may not come up after a reboot. PR1446755

  • Some of the random 40/100G interface may not come up when the trying to commit the configuration that has inet,mtu and speed (any or all) . The work around for this issue is to delete the speed configuration on the problem interfaces and add the speed configuration. PR1454412

  • After committing the speed related configuration for all 32 ports, some interfaces may remain down. Workarounds: Option 1: Apply the port speed configuration change at a lesser scale (up to 10 interfaces). Option 2: Reboot with the applied IPCLOS configuration. Option 3: Flap the link via link disable and re-enable the configuration (set interface et-x/y/z disable; commit / delete interface et-x/y/z disable; commit) PR1461868