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Junos OS Release Notes for ACX Series

 

These release notes accompany Junos OS Release 20.1R1 for the ACX Series. They describe new and changed features, limitations, and known and resolved problems in the hardware and software.

You can also find these release notes on the Juniper Networks Junos OS Documentation webpage, located at https://www.juniper.net/documentation/product/en_US/junos-os.

What's New

Learn about new features introduced in the Junos OS main and maintenance releases for ACX Series routers.

Interfaces and Chassis

  • Support for new show | display set CLI commands (ACX-Series, SRX Series, QFX Series, PTX Series, and MX Series)—Starting in Junos OS Release 20.1R1, the following new show CLI commands have been introduced:

    • show | display set explicit—Display all the configurations explicitly that the system internally creates when you configure certain commands in a single line.

    • show | display set relative explicit—Display all the configurations explicitly that the system internally creates when you configure certain commands in a single line.

    [See show | display set and show | display set relative.]

Junos OS XML API and Scripting

  • The jcs:load-configuration template supports loading the rescue configuration (ACX Series, EX Series, MX Series, PTX Series, QFX Series, and SRX Series)—Starting in Junos OS Release 20.1R1, the jcs:load-configuration template supports the rescue parameter to load and commit the rescue configuration on a device. SLAX and XSLT scripts can call the jcs:load-configuration template with the rescue parameter set to "rescue" to replace the active configuration with the rescue configuration.

    [See Changing the Configuration Using SLAX and XSLT Scripts and jcs:load-configuration Template.]

Junos Telemetry Interface

  • gRPC Dial-Out support on JTI (ACX Series, MX Series, PTX Series, QFX Series)—Junos OS Release 20.1R1 provides gRPC Dial-Out support for telemetry. In contrast to the gNMI Dial-In feature, where the collector (client) initiates a connection to the target device (server) to perform a gNMI subscription operation for telemetry data, the gRPC Dial-Out feature initiates the request for telemetry data in a reverse fashion. The target device initiates a gRPC session with the client, and when the session is established, streams the telemetry data that is specified by the sensor-group subscription to the collector.

    gRPC Dial-Out provides several benefits as compared to gRPC Dial-In:

    • Reduces the exposure of target devices to threats outside of their topology.

    • Simplifies access to a target device, which, if the gRPC Dial-In method is used, would require a collector to overcome a series of complex firewall configurations to gain access to the target device.

    • Collectors can be stateless; without the need to initiate a session, they simply listen, subscribe, and store collected data.

    • Supports encryption statistics to an outside collector.

    To enable export of statistics, include the export-profile and sensor option at the [edit services analytics] hierarchy level. The export profile should include the reporting rate, the transport service (like gRPC), and the format (like gbp-gnmi). The sensor configuration should include the name of the collector (the server’s name), the name of the export profile, and the resource path (sensor name), such as /interfaces/interface[name='fxp0'].

    [See Using gRPC Dial-Out.]

  • gRPC version v1.18.0 supported with JTI (ACX Series, MX Series, PTX Series, QFX Series)—Junos OS Release 20.1R1 includes support for remote procedure call (gRPC) services version v1.18.0 with Junos telemetry interface (JTI). Important enhancements for gRPC are included in version v1.18.0. Previously, JTI was supported with gRPC version v1.3.0.

    Use gRPC in combination with JTI to stream statistics at configurable intervals from a device to an outside collector.

    [See gRPC Services for Junos Telemetry Interface.]

Routing Protocols

  • Support for Topology-Independent Loop-Free Alternate (TI-LFA) in IS-IS for IPv6-only networks (ACX Series, MX Series, PTX Series)— Starting with Junos OS Release 20.1R1, you can configure TI-LFA with segment routing in an IPv6-only network for the IS-IS protocol. TI-LFA provides fast reroute (FRR) backup paths corresponding to the post-convergence path for a given failure. TI-LFA provides protection against link failure, and node failure.

    You can enable TI-LFA for IS-IS by configuring use-post-convergence-lfa statement at the [edit protocols isis backup-spf-options] hierarchy level. You can enable the creation of post-convergence backup paths for a given IPv6 interface by configuring the post-convergence-lfa statement at the [edit protocols isis interface interface-name level level] hierarchy level. The post-convergence-lfa statement enables link-protection mode.

    You can enable node-protection mode for a given interface at the [edit protocols isis interface interface-name level level post-convergence-lfa] hierarchy level. However, you cannot configure fate-sharing protection for IPv6-only networks.

    [See Understanding Topology-Independent Loop-Free Alternate with Segment Routing for IS-IS]

What's Changed

There are no changes in behavior and syntax for ACX Series in Junos OS Release 20.1R1.

Known Limitations

Learn about known limitations in this release for ACX Series routers.

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

General Routing

  • ACX6360 Junos telemetry interface or telemetry infrastructure does not support the interface-filtering capability. Therefore, after you enable a particular sensor for telemetry, it is turned on for all the interfaces. PR1371996

  • ACX Series routers support only 900 joins of IGMPv3 users per second. PR1448146

Open Issues

Learn about open issues in this release for ACX Series routers.

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

General Routing

  • On ACX Series routers, which are acting as PE routers for Layer 2 VPN, Layer 2 circuit, VPLS, and Layer 3 VPN services, traffic forwarding over the MPLS paths used by these services can be stopped. you experience the traffic forwarding issue when the LSP flaps between the primary and the backup paths in a particular sequence. PR1204714

  • The link fault signaling (LFS) feature is not supported on ACX5448 10-Gigabit, 40-Gigabit, and 100-Gigabit Ethernetinterfaces. PR1401718

  • When timing configuration and corresponding interface configurations are flapped for multiple times in iteration, PTP is stuck in INITIALIZE state where the ARP for the neighbor is not resolved. In the issue state, BCM hardware block gets into inconsistency state, where the lookup fails. PR1410746

  • CoS table error might sometimes cause traffic outages and SNMP timeouts, if the optic module is plugged out and inserted back. PR1418696

  • On ACX5000 platform, the high CPU usage by the fxpc process might be seen under a rare condition if parity errors are detected in devices. It has no direct service/traffic impact. However, because CPU utilization is high when this issue occurs, there are some side effects. For example, the issue could impact time-sensitive features such as BFD. PR1419761

  • The configuration of em2 interface causes the FPC to crash during initialization and the FPC does not come online. After you delete the em2 configuration and restar the router, the FPC comes online. PR1429212

  • Memory leaks are expected in Junos OS Release 20.1R1. PR1438358

  • On an ACX5448, link flaps or CoS configuration changes (specific to temporal value changes) might result in traffic drop on all interfaces and be recorded as RED drops. PR1443466

  • Recovery of Junos OS volume is not possible from the OAM menu. PR1446512

  • Issue seen while performing unified ISSU to Junos OS Release 20.1, ISSU is completed, but the Packet Forwarding Engine does not function. PR1483959

  • On an ACX5448 platform, the Layer 2 VPN application with ethernet-ccc input-vlan-map/output-vlan-map can experience traffic to be discarded silently while the control plane is still up. PR1485444

Resolved Issues

Learn which issues were resolved in the Junos OS main and maintenance releases for ACX Series routers.

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

General Routing

  • On ACX5000 routers, the internal error MacDrainTimeOut and bcm_port_update failed is seen. PR1284590

  • High CPU utilization is seen for fxpc processes with CoS changes on the aggregated Ethernet interfaces. PR1407098

  • The optics module comes with Tx enabled by default. As the port is administratively disabled, the port is stopped but as the port has not been started, it does not disable Tx. PR1411015

  • The l2cpd process might crash and generate a core file when interfaces flap. PR1431355

  • ACX5448:DHCP packets are not transparent over Layer 2CIRCUIT. PR1439518

  • ACX5448:Encapsulation flexible VLAN tagging is not supported with MPLS family, need to provide commit ERROR. PR1445046

  • Fans on an ACX5448-M might not be running at the correct speed. PR1448884

  • The oper-state for et interface do not transition from 'init' to 'Normal'. PR1449937

  • ACX5448-D interfaces support: After disabling the 100 Gigabit and the 40 Gigabit interface laser output power in show interfaces diagnostics optics shows some values. PR1452323

  • ACX5048 snmp polling will be stalled after the link flap or sfp replacement and ACX_COS_HALP(acx_cos_gport_sched_set_strict_priority:987): Failed to detach logs will be seen. PR1455722

  • ACX5448-D and ACX5448-M devices do not display airflow information and temperature sensors as expected. PR1456593

  • ACX5448 Layer 2 VPN with encapsulation-type ethernet, stops passing traffic after a random port is added with VLAN configuration. PR1456624

  • The rpd crash might be seen if BGP route is resolved over same prefix protocol next-hop in inet.3 table that has both RSVP and LDP routes. PR1458595

  • Route resolve resolution is not happening when the packet size is 10000. PR1458744

  • The traffic might be discarded silently during link recovery in an open ethernet access ring with ERPS configured. PR1459446

  • ACX5K: SNMP mib walk for jnxOperatingTemp is not returning anything for FPC in new versions. PR1460391

  • ACX5448-M Interfaces and Optics support: on enabling local loopback, the 10 Gigabit interface is going down. PR1460715

  • ACX5448-D interfaces and optics support: sometimes when you bring up theaggregated Ethernet interface, there are ARP resolution issue. PR1461485

  • ACX platform LLDP neighbour not up on lag after software upgrade to Junos OS Release 18.2R3-S1. PR1461831

  • Not able to add more than 16 links in a lag. PR1463253

  • Memory leak on l2cpd process might lead to l2cpd crash. PR1469635

  • RED drop on interface is seen even without any congestion. PR1470619

  • Egress queue statistics are not applicable to aggregated Ethernet interface on model ACX5048. PR1472467

  • The dcpfe core is seen when disabling or enabling MACsec through Toby scripts. PR1479710

Interfaces and Chassis

  • MC-AE interface might be shown as unknown status if adding the sub-interface as part of the VLAN on the peer MC-AE node. PR1479012

Layer 2 Ethernet Services

  • Member links state might be asychronized on a connection between PE and CE in an EVPN A/A scenario. PR1463791

Routing Protocols

  • The rpd might crash continuously because of memory corruption in the IS-IS setup. PR1455432

Documentation Updates

There are no errata or changes in Junos OS Release 20.1R1 documentation for the ACX Series.

Migration, Upgrade, and Downgrade Instructions

This section contains the upgrade and downgrade support policy for Junos OS for the ACX Series Router. Upgrading or downgrading Junos OS might take several minutes, depending on the size and configuration of the network.

For information about software installation and upgrade, see the Installation and Upgrade Guide.

Upgrade and Downgrade Support Policy for Junos OS Releases

Support for upgrades and downgrades that span more than three Junos OS releases at a time is not provided, except for releases that are designated as Extended End-of-Life (EEOL) releases. EEOL releases provide direct upgrade and downgrade paths—you can upgrade directly from one EEOL release to the next EEOL release even though EEOL releases generally occur in increments beyond three releases.

You can upgrade or downgrade to the EEOL release that occurs directly before or after the currently installed EEOL release, or to two EEOL releases before or after. For example, Junos OS Releases 17.1, 17.2, and 17.3 are EEOL releases. You can upgrade from Junos OS Release 17.1 to Release 17.2 or from Junos OS Release 17.1 to Release 17.3.

You cannot upgrade directly from a non-EEOL release to a release that is more than three releases ahead or behind. To upgrade or downgrade from a non-EEOL release to a release more than three releases before or after, first upgrade to the next EEOL release and then upgrade or downgrade from that EEOL release to your target release.

For more information about EEOL releases and to review a list of EEOL releases, see https://www.juniper.net/support/eol/junos.html.

For information about software installation and upgrade, see the Installation and Upgrade Guide.