Junos OS Release Notes for ACX Series

 

These release notes accompany Junos OS Release 17.4R2 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.

New and Changed Features

This section describes the new features and enhancements to existing features in the Junos OS main release and the maintenance releases for ACX Series Universal Metro Routers.

Release 17.4R2 New and Changed Features

There are no new features or enhancements to existing features for ACX Series in Junos OS Release 17.4R2.

Release 17.4R1 New and Changed Features

Management

  • Support for multiple, smaller configuration YANG modules (ACX Series)—Starting in Junos OS Release 17.4R1, the YANG module for the Junos OS configuration schema is split into a root configuration module that is augmented by multiple, smaller modules. The root configuration module comprises the top-level configuration node and any nodes that are not emitted as separate modules. Separate, smaller modules augment the root configuration module for the different configuration statement hierarchies. Smaller configuration modules enable YANG tools and utilities to more quickly and efficiently compile and work with the modules, because they only need to import the modules required for the current operation.

    [See Understanding the YANG Modules That Define the Junos OS Configuration.]

Timing and Synchronization

  • Enterprise profile for Precision Time Protocol (PTP) (ACX1100 Router)—Starting with Junos OS Release 17.4R1, the enterprise profile, which is based on PTPv2, provides the ability for enterprise and financial markets to timestamp on different systems and to handle a range of latency and delays. The enterprise profile supports the following options:

    • IPv4 multicast transport

    • Boundary clocks

    • 512 downstream slave clocks

    You can enable the enterprise profile at the [edit protocols ptp profile-type] hierarchy.

    Note

    On ACX Series, the enterprise profile for PTP is supported only on ACX1100 AC router.

Changes in Behavior and Syntax

This section lists the changes in behavior of Junos OS features and changes in the syntax of Junos OS statements and commands from Junos OS Release 17.4R2 for the ACX Series Universal Metro Routers.

Management

  • Changes to Junos OS YANG module naming conventions (ACX Series)—Starting in Junos OS Release 17.4R1, the native Junos OS YANG modules use a new naming convention for the module's name, filename, and namespace. The module name and filename include the device family and the area of the configuration or command hierarchy to which the schema in the module belongs. In addition, the module filename includes a revision date. The module namespace is simplified to include the device family, the module type, and an identifier that is unique to each module and that differentiates the namespace of the module from that of other modules.

    [See Understanding Junos OS YANG Modules.]

Security

  • Support to log the SSH key changes—Starting with Junos OS 17.4R1, the configuration statement log-key-changes is introduced at the [edit system services ssh ] hierarchy level. When the log-key-changes configuration statement is enabled and committed (with the commit command in configuration mode), Junos OS logs the changes to the set of authorized SSH keys for each user (including the keys that were added or removed). Junos OS logs the differences since the last time the log-key-changes configuration statement was enabled. If the log-key-changes configuration statement was never enabled, then Junos OS logs all the authorized SSH keys.

Subscriber Management and Services

  • DHCPv6 lease renewal for separate IA renew requests (ACX Series)—Starting in Junos OS Release 17.4R2, the jdhcpd process handles the second renew request differently in the situation where the DHCPv6 client CPE device does both of the following:

    • Initiates negotiation for both the IA_NA and IA_PD address types in a single solicit message.

    • Sends separate lease renew requests for the IA_NA and the IA_PD and the renew requests are received back-to-back.

    The new behavior is as follows:

    1. When the reply is received for the first renew request, if a renew request is pending for the second address type, the client stays in the renewing state, the lease is extended for the first IA, and the client entry is updated.

    2. When the reply is received for the second renew request, the lease is extended for the second IA and the client entry is updated again.

    In earlier releases:

    1. The client transitions to the bound state instead of staying in the renewing state. The lease is extended for the first IA and the client entry is updated.

    2. When the reply is received for the second renew request, the lease is not renewed for the second address type and the reply is forwarded to the client. Consequently, when that lease ages out, the binding for that address type is cleared, the access route is removed, and subsequent traffic is dropped for that address or address prefix.

    [See Using DHCPv6 IA_NA with DHCPv6 Prefix Delegation Overview.]

Known Behavior

There are no known limitations in Junos OS Release 17.4R2 for the ACX Series.

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

Known Issues

This section lists the known issues in hardware and software in Junos OS Release 17.4R2 for the ACX Series Universal Metro Routers.

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

Interfaces and Chassis

  • On ACX Series router, when link-speed is configured explicitly, aggregate interface goes down permanently after reboot. PR1022248

  • In a normal software MAC learning mode, when incremental MAC traffic of range higher than the profile is received, then after feb restart the MAC entries is not seen in the software table, although present in the hardware table. As a workaround, in the hardware MAC learning mode, delete the routing instance and reconfigure it again to make the MAC entries seen in the software table. In the software MAC learning mode, deactivate the routing instance, clear the pending entries or allow the pending entries to be aged out and then activate the routing instance to solve this issue. PR1277436

  • On ACX Series PE routers with Layer 3 VPN configured, when running traceroute on ingress PE to CE, only P hop and CE are displayed. The PE information is not displayed. This is a hardware limitation and a workaround is not available.PR1313013

Resolved Issues

There are no fixed issues in Junos OS 17.4R2 for ACX Series.

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

Documentation Updates

There are no errata or changes in Junos OS Release 17.4R2 for the ACX Series documentation.

Migration, Upgrade, and Downgrade Instructions

This section contains the upgrade and downgrade support policy for Junos OS for the ACX Series Universal Metro Routers. 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. However, you cannot upgrade directly from a non-EEOL 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.

Product Compatibility

Hardware Compatibility

To obtain information about the components that are supported on the devices, and the special compatibility guidelines with the release, see the Hardware Guide for the product.

To determine the features supported on ACX Series routers in this release, use the Juniper Networks Feature Explorer, a Web-based application that helps you to explore and compare Junos OS feature information to find the right software release and hardware platform for your network. Find Feature Explorer at https://pathfinder.juniper.net/feature-explorer/.

Hardware Compatibility Tool

For a hardware compatibility matrix for optical interfaces and transceivers supported across all platforms, see the Hardware Compatibility tool.