Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?


What’s Changed in Release 21.1R2


  • Minimum auto-recovery time reduced for duplicate MAC address detection (ACX Series, PTX Series and QFX Series)—Junos OS has changed the minimum value allowed for auto-recovery time for duplicate MAC address detection from 5 minutes to 1 minute. The auto-recovery time is the length of time that the device suppresses a duplicate MAC address. Reducing the auto-recovery time allows customers to quickly recover from a MAC address duplication state. You configure the auto-recovery-time option under the duplicate-mac-detection statement at the edit routing-instances routing-instance-name protocols evpn or edit protocols evpn hierarchy.

    [See Changing Duplicate MAC Address Detection Settings .]

General Routing

  • Enhancement to the show interfaces (Aggregated Ethernet) command (PTX Series and QFX Series)—When you run the show interfaces extensive command for aggregated Ethernet interfaces, you can now view following additional fields for MAC statistics : Receive, Transmit, Broadcast and Multicast packets.

    [See show chassis pic.]

  • Enhancement to the default remnant-holdtime (Junos OS Evolved platforms: QFX5130-32CD, and QFX5220)— Starting this release, the default remnant-holdtime has been increased from 180 seconds to 300 seconds. This provides sufficient time for protocols to start and sync routes from neighbors in a scaled environment, during rpd restart. You can configure remnant-holdtime at the edit routing-options forwarding-table hierarchy level.

    See forwarding-table .]

Interfaces and Chassis

  • Fabric OAM is disabled by default (PTX10003-80C and PTX10003-160C)—We've disabled the fabric Operation, Administration, Maintenance (OAM) feature. Therefore, the CLI command set chassis fabric oam detection-disable is not functional as the feature remains disabled by default in this release. In Junos OS Evolved Release 20.4R1, the fabric OAM feature, which helps in detecting failures in fabric paths, was enabled by default.

    [See Error Handling by Fabric OAM.]

Junos Telemetry Interface

You can enter zero suppression no-zero-suppression at the edit services analytics hierarchy level to disable zero suppression for gRPC-based sensors. When this feature is enabled, data for a sensor is sent to the collector if the sensor value is zero. All key value pair updates will be streamed to a collector without performing any zero suppression.

To enable zero suppression again (the default), delete the configuration by entering delete services analytics zero-suppression no-zero-suppression.

Whenever this feature is set or deleted, any existing collector is disconnected.

Network Management and Monitoring

  • Fault alarm generated for feed failure on a DC power supply (PTX10008)—A fault alarm is generated when only one of the feeds on a DC power supply (A0 and B0 or A1 and B1) is faulty.

  • Changes in contextEngineID for SNMPv3 INFORMS (ACX Series, PTX Series, QFX Series)— Now the contextEngineID of SNMPv3 INFORMS is set to the local engine-id of Junos devices. In earlier releases, the contextEngineID of SNMPv3 INFORMS was set to remote engine-id.

    [See SNMP MIBs and Traps Supported by Junos OS.]