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Junos OS Release Notes for ACX Series


These release notes accompany Junos OS Release 18.4R3 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

New and Changed Features

This section describes the features and enhancements in Junos OS Release 18.4R3 for ACX Series Universal Metro Routers.

New and Changed Features: 18.4R3

There are no new features or enhancements to existing features for ACX Series in Junos OS Release 18.4R3.

New and Changed Features: 18.4R2

Interfaces and Chassis

  • Support for 100-Mbps and 1-Gbps speeds on Tri-Rate Copper SFP (ACX5448)—In Junos OS Release 18.4R2, ACX5448 routers support 100-Mbps and 1-Gbps speeds on Tri-Rate Copper SFP optics (740-013111). Note that 100-Mbps speed is supported only from ports xe-0/0/24 through xe-0/0/47.


    10-Mbps speed is not supported on Tri-Rate Copper SFP transceivers due to hardware limitations.

    • To set the speed for the optics, issue the set interfaces interface-name speed auto command. See speed for more details.

    • To enable autonegotiation, issue the set interfaces interface-name gigether-options auto-negotiation command. See auto-negotiation.

Software Installation and Upgrade

  • Zero Touch Provisioning (ACX5448)—Starting in Junos OS Release 18.4R2, Zero Touch Provisioning (ZTP) automates the provisioning of the device configuration and software image with minimal manual intervention on management interface em0.

    When you physically connect a router to the network and boot it with a factory configuration, the router upgrades the Junos OS software image automatically and autoinstalls configuration file from the network through the management interface.

Timing and Synchronization

  • Transparent clock over IPv6 support (ACX5448)—Starting with Junos OS Release 18.4R2, ACX5448 routers support transparent clock functionality for PTP over IPv6.

    To configure the transparent clock functionality, you must include the e2e-transparent statement at the [edit protocol ptp] hierarchy level.

    Use the show ptp global-information command to check the status of the transparent clock functionality configured on the router.

    [See Understanding Transparent Clocks in Precision Time Protocol.]

New and Changed Features: 18.4R1

Authentication, Authorizing, and Accounting (AAA)

  • Support for password change policy enhancement (ACX Series)—Starting in Junos OS Release 18.4R1, the Junos OS password change policy for local user accounts is enhanced to comply with additional password policies. As part of the policy improvement, you can configure the following:

    • maximum-lifetime-value—The maximum duration of a password. The password expires after the maximum is reached.

    • minimum-lifetime-value—The minimum duration of a password. You cannot change the password until the minimum duration is reached.

    [See password.]

Interfaces and Chassis

  • Multichassis link aggregation groups, configuration synchronization, and configuration consistency check (MC-LAG) (ACX5448 routers)—Starting in Junos OS Release 18.4R1, MC-LAG enables a client device to form a logical LAG interface using two switches. MC-LAG provides redundancy and load balancing between the two switches, multihoming support, and a loop-free Layer 2 network without running spanning tree protocols (STP).

    [See Multichassis Link Aggregation Features, Terms, and Best Practices .]


  • Support for topology independent loop-free alternate (TI-LFA) for IS-IS, advertising MPLS labels (ISIS, OSPF), and configuring SRGB for SPRING (ISIS, OSPF) (ACX5448)—Starting with Junos OS Release 18.4R1, ACX5448 router support topology independent (TI)-loop-free alternate (LFA), advertise MPLS labels (ISIS, OSPF), and segment routing global block (SRGB) for SPRING (ISIS, OSPF).

    Topology independent (TI)-loop-free alternate (LFA) with segment routing provides fast reroute (FRR) backup paths corresponding to the post-convergence path for a given 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 configure SRGB range label used by source packet routing in networking (SPRING). The labels from this SRGB range is used for SPRING in IS-IS domain. This way the labels advertised in the segment routing is more predictable and deterministic across the segment routing domain.

    • To configure the starting index value of the SRGB label block, use the start-label start-label-block-value statement at the [edit protocols isis source-packet-routing srgb] hierarchy level.

    • To configure the index range of the SRGB label block, use the index-range value configuration statement at the [edit protocols isis source-packet-routing srgb] hierarchy level.

    ACX5448 router supports IS-IS and OSPF segment routing enabled through MPLS. IS-IS and OSPF creates an adjacency segment per IS-IS and OSPF neighbor, for a given interface, adjacency, and area. A separate MPLS label is allocated for each adjacency segment created.

    To configure OSPF segment routing, use the following configuration statements at the [edit protocols ospf] hierarchy level:

    • source-packet-routing—Enable the source packet routing feature.

    • node-segment—Enable the node segment.

    To configure IS-IS segment routing, use the following configuration statements at the [edit protocols isis] hierarchy level:

    • source-packet-routing—Enable the source packet routing feature.

    • node-segment—Enable source packet routing at all levels.

    [See Understanding Topology-Independent Loop-Free Alternate with Segment Routing for IS-IS, Understanding Source Packet Routing in Networking (SPRING), and source-packet-routing (Protocols IS-IS and OSPF).]

Platform and Infrastructure

  • DMA recovery mechanism (ACX Series)—A recovery mechanism has been introduced that is triggered in case the router enters an Idle state on any DMA channels. The recovery mechanism reboots the PFE to recover from Idle state.

    The following recovery message is logged in the RE syslog message:

    The following recovery message is logged in the PFE syslog message:

Routing Protocols

Timing and Synchronization

  • Support for PTP boundary clocks for phase and time synchronization (ACX5448)—Starting with Junos OS Release 18.4R1, ACX5448 routers support PTP boundary clocks for phase and time synchronization using IEEE-1588 Precision Timing Protocol (PTP). This feature also supports:

    • PTP over IPv4 (IEEE-1588v2)

    • PTP ordinary and boundary clocks

    • One-step clock mode operation for the PTP master clock

    • 10-MHz and 1-PPS output for measurement purpose

    All PTP packets use the best-effort queue instead of the network control queue.

    The ACX5448 router does not support the following features:

    • Hybrid mode

    • Boundary clock performance complying with G.8273.2

    • Dual-tagged PTP over IPv4

    [See IEEE 1588v2 PTP Boundary Clock Overview.]


  • Support to control traceroute over Layer 3 VPN (ACX Series)—Starting in Junos OS Release 18.4R1, in a Layer 3 VPN topology with vrf-table-label configured and multiple customer edge (CE) routers configured in the same VPN routing and forwarding (VRF) routing instance, when traceroute is performed to a remote provider edge (PE) router for a CE-facing network, the ICMP time exceeded packet determines the correct IP address as the source address.

    To control the traceroute over Layer 3 VPN topology with vrf-table-label configured and multiple CE routers configured in the same VRF, you can configure allow-l3vpn-traceroute-src-select at the[edit system] hierarchy level that determines the correct IP source address by reviewing the destination routing instance and destination IP address.

    [See allow-l3vpn-traceroute-src-select.]

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 18.4R3 for the ACX Series routers.

Changes in Behavior and Syntax: 18.4R3

Interfaces and Chassis

  • Support for disabling RS-FEC (ACX6360-OX)—By default, Junos OS enables or disables forward error correction based on plugged-in optics. Starting with Junos OS Release 18.4R3, on ACX6360-OX transponders, you can now disable Ethernet FEC, also known as RS-FEC or FEC91. In releases before Junos OS Release 18.4R3, RS-FEC is enabled by default and cannot be disabled.

    [See fec.]

Routing Protocols

  • Advertising /32 secondary loopback addresses to traffic engineering database as prefixes (ACX Series, EX Series, MX Series, PTX Series, QFX Series, and SRX Series)—We've made changes to export multiple loopback addresses to the lsdist.0 and lsdist.1 routing tables as prefixes. This eliminates the issue of advertising secondary loopback addresses as router IDs instead of prefixes. In earlier releases, multiple secondary loopback addresses in the traffic engineering database were added to the lsdist.0 and lsdist.1 routing tables as part of node characteristics and advertised them as the router ID.

Changes in Behavior and Syntax: 18.4R2

Interfaces and Chassis

  • Support for creating layer 2 logical interface independently (ACX Series, EX Series, MX Series, PTX Series, and QFX Series)—In Junos OS Releases 18.4R1, 18.4R2 and later, ACX Series routers support creating Layer 2 logical interfaces independent of the Layer 2 routing-instance type. That is, you can configure and commit the Layer 2 logical interfaces separately and add the interfaces to the bridge domain or Ethernet VPN (EVPN) routing instance separately. Note that the Layer 2 logical interfaces work fine only when they are added to the bridge domain or EVPN routing instance.

    In earlier Junos OS releases, when you use a Layer 2 logical interface configuration (units with encapsulation vlan-bridge configuration), then you must add the logical interface as part of a bridge domain or EVPN routing instance for the commit to succeed.

Operation, Administration, and Maintenance (OAM)

  • Performance monitoring history data is lost when a change in number of supported history records is detected (ACX Series and MX Series)—In Junos OS Release 18.4R2, when Ethernet connectivity fault management starts, it detects the number of history records supported by the existing performance monitoring history database and if there is any change from the number of history records supported (that is, 12) in Release 18.4R2, then the existing performance monitoring history database is cleared and all performance monitoring sessions are restarted with mi-index 1.

Routing Protocols

  • Change in the default behavior of advertise-from-main-vpn-tables configuration statement—BGP now advertises EVPN routes from the main bgp.evpn .0 table. You can no longer configure BGP to advertise the EVPN routes from the routing instance table. In earlier Junos OS Releases, BGP advertised EVPN routes from the routing instance table by default.

    [See advertise-from-main-vpn-tables.]

Changes in Behavior and Syntax: 18.4R1

Network Management and Monitoring

  • The NETCONF server omits warnings in RPC replies when the rfc-compliant statement is configured and the operation returns <ok/> (ACX Series)—Starting in Junos OS Release 18.4R1, when you configure the rfc-compliant statement at the [edit system services netconf] hierarchy level to enforce certain behaviors by the NETCONF server, the server must not return an RPC reply that encloses both an <rpc-error> element and an <ok/> element. If the operation is successful, but the server reply would enclose one or more <rpc-error> elements of severity warning in addition to the <ok/> element, then the warnings are omitted. In earlier releases, or when the rfc-compliant statement is not configured, the NETCONF server might issue an RPC reply that encloses both an <rpc-error> element of severity warning and an <ok/> element.

  • SNMP customization configuration introduced (ACX Series)—In Junos OS Release 18.4R1, we have introduced the CLI configuration command set snmp customization ether-stats-ifd-only. When ether-stats-ifd-only is configured, the show snmp mib walk etherstatsTable command displays data only for physical interfaces.

    [See customization (SNMP).]

Known Behavior

This section lists known behavior, system maximums, and limitations in hardware and software in Junos OS Release 18.4R3 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.

General Routing

  • When Layer 3 packets are classified, DiffServ code points are not preserved but are getting lost at the egress interface because of a chipset limitation. PR1322142

  • ARP learning rate is very low. PR1343221

  • All PTP packets goes to the best-effort queue instead of Network Control queue. This is because of the limitation on Qumran where DSCP values are not preserved. PR1361315

  • 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

  • For et-interfaces, only PRE_FEC_SD defect is raised and no OTN alarm is raised. PR1371997

  • The CLI static-cak command encryption does not work between two ACX-OX transpoder nodes. PR1389802

  • For ACX6360 TIC beacon port-range needs to be updated to 0-7 instead of 0-15. PR1399335

  • If the user configures an invalid speed configuration on TIC ports (PIC slot 1) on ACX6360-OR/OX, the TIC interfaces are not created. PR1403546

  • Junos OS does not perform VLAN IDcheck at egress and VLAN ID check is performed only at ingress. PR1403730

  • Single physical interface and logical interface for both ICCP and ICL are not supported on ACX5448 platform. Only in this model, static ARP configuration to peer IRB IP is required. PR1410971

  • ACX5448 forwarding-class defaults setup in schema file for ACX5448. Therefore, it is expected to see a firewall process LIBCOS_COS_ errors are seen while upgrading the devices with latest software image/build when it is attempted to read pvidb db. PR1422284

  • On Ethernet bridge, L2 filters might not work as expected when trying to match VLAN-based fields for untagged packets. PR1423214

  • Some TPIDs (for example, TPID 9200) are not supported with VLAN-CCC and some of the other features. As these TPIDs are not supported, rewrite is not possible on those TPIDs. PR1433500

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

Routing Protocols

  • When multiple adjacencies are coming-up or flapping, some routes might not have remote-lfa backup next hops. They will appear only after next SPF trigger either manually or through network event. PR1389392

Known Issues

This section lists the known issues in hardware and software in Junos OS Release 18.4R3 for the ACX Series Router.

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

General Routing

  • Forwarding when using a non-existing SSM map source address in IGMPv3 instead of pruning. PR1126699

  • ACX5448: When 1G SFP is plugged in the router, autonegotiation is enabled by default. There is no functional impact. Only the CLI show interfaces intf-name extensive command will show the autonegotiation field as disabled. PR1343679

  • Loopback status is not shown for OT interfaces on CLI (available from vty only). PR1358017

  • Dedicated minimum buffers are reserved for some queues according to the Junos OS working model. These buffers are always available to those queues irrespective of the traffic pattern throughout the system. When the clearing stat statement is used, these values are visible. This cosmetic or minor issue has no functional impact is seen. PR1367978

  • The SD (Signal Degrade) threshold is normally lower than the SF threshold (that is, so that as errors increase, SD condition is encountered first). For the ACX6360 optical links there is no guard code to prevent the user from setting the SD threshold above the SF threshold, which would cause increasing errors to trigger the SF alarm before the SD alarm. This will not cause any issues on systems with correctly provisioned SD/SF thresholds. PR1376869

  • Enhancement is needed for FRR BER threshold SNMP support. PR1383303

  • On ACX6360 router, Tx power cannot be configured using + sign. PR1383980

  • The switchover time observed was more than 50 ms under certain soak test conditions with an increased scale with a multi-protocol multi-router topology. PR1387858

  • The ccc logs are not compressed after rotation. PR1398511

  • A jnxIfOtnOperState trap notification is sent for all ot-interfaces. PR1406758

  • High CPU use for FXPC processes with class-of-service changes on aggregated Ethernet interfaces. PR1407098

  • Layer 2 rewrite is happening on regular bridge domain and VLAN interfaces, though there are some service dependencies (VPLS in this case) in which egress interface map table is not updated properly with Layer 2 rewrite map ID that causes rewrite not to be working. PR1414414

  • On ACX5448 devices, the zero-touch provisioning (ZTP) process will proceed with image upgrade even in situations when there is a mismatch in platform name of the software image stored on FTP or ZTP servers and the actual platform where the ZTP process is being run. PR1418313

  • It is an interoperability issue between ACX5448 router and MX Series router. Configure the speed on remote end before LACP configurations. PR1429106

  • Issue is seen when restart routing is triggered in both the MC-LAG peers, which means both the MC LAG peers go down. Also, the issue is seen when there is a burst of traffic due to rapid IGMP joins sent from a Spirent device. These two scenarios are highly unlikey in field/customer site. PR1431935

  • Protocols get forwarded when using non-existing SSM map source address in IGMPv3 instead of pruning. PR1435648

  • On ACX5448 router, after issuing deactivate/activate class-of-service, traffic drop might be seen. PR1436494

  • Core file from dcpfe_pd can be triggered when IFD detach happens on MACsec enabled interface. IFD detach happens when interface speed changes, Flexible PIC Concentrator (FPC) restarts, or PIC restarts. PR1452275

  • It is not possible to form 125,000 IGMP groups with ACX5448 router receiving 125,000 IGMP v2 reports per second. This is a product limitation from BCM and CPU host path queuing model. PR1454465

  • Link does not come up when 100-Gigabit Ethernet is channelized to 4x25-Gigabit Ethernet interfaces. PR1479733

Resolved Issues

This section lists the issues fixed in Junos OS 18.4R3 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.

Resolved Issues:18.4R3

General Routing

  • On ACX5000, an internal error MacDrainTimeOut and bcm_port_update failed is observed. PR1284590

  • The bcmDPC task is high even though interrupt START_BY_START flag set to 0. PR1329656

  • The aggregated Ethernet interface with LACP stays down after the router reboots if link-speed is configured. PR1357012

  • On ACX Series routers, the LED on a Gigabit Ethernet interface goes down when 10-Mbps speed is configured. PR1385855

  • Link Fault Signaling (LFS) is not working on ACX5448 routers with 10-Gigabit Ethernet, 40-Gigabit Ethernet, or 100-Gigabit Ethernet interfaces. PR1401718

  • The optic 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 40-GIgabit Ethernet FEC on ACX5448 is ON by default. Need to align with MX Series and QFX Series platforms where FEC is NONE. PR1414649

  • 96,000 ARPs get populated and only 47,000 next-hop entries are present. So, around 50 percent packet drop is observed. PR1426734

  • On ACX5448 devices, up on reboot of an MC_LAG peer, when the peer comes up (but before hardware comes up), there is a 10–20 second traffic hit on node1. PR1430910

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

  • ACX5448 might malfunction in encapsulating small packets if egress link is 40G/100G. PR1434900

  • In ACX Series platforms, no-vrf-propagate-ttl might not work after activating or deactivating CoS configuration. PR1435791

  • Interface on ACX1100 router remains down when SFP-1FE-FX (740-021487) is used. PR1439384

  • On ACX5448 routers, DHCP packets are not transparent over Layer 2 circuit. PR1439518

  • On ACX5448 routers, packet buffer error from Packet Forwarding Engine is leading to memory leak when IGMP is sent from NNI AC in L2 circuit and VPLS. PR1442901

  • RED drops might be seen after link flaps or CoS configuration changes. PR1443466

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

  • On ACX5448 routers, Junos OS Release 18.3R1-S4.1 does not perform proper dot1p CoS rewrite on interfaces configured with l2circuit/local-switching/family ccc. PR1445979

  • In ACX Series platforms, auto exported route between VRFs might not reply to ICMP echo requests. PR1446043

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

  • On ACX5448 routers, Layer 2 circuit stops forwarding traffic after LDP flap. PR1448899

  • The Layer 2 circuit with backup-neighbor (hot-standby) configured might stop forwarding traffic after failovers. PR1449681

  • An FPC core file might be seen after changing the configuration of PTP/SyncE. PR1451950

  • ACX5448 FPC crashed due to segmentation fault. PR1453766

  • Enable gigether option to configure Ethernet FEC on client ports. PR1456293

  • The ACX5448 Layer 2 VPN with encapsulation type Ethernet stops passing traffic after adding a random port with VLAN configuration. PR1456624

  • The traffic might get silently dropped or discarded during link recovery in an open Ethernet access ring with ERPS configured. PR1459446

  • On the ACX5000 routers, SNMP MIB walk for jnxOperatingTemp does not return any values for FPC in the new versions. PR1460391

  • On ACX Series platform, LLDP neighbor does not recover on a LAG after the software is upgraded to Junos OS Release 18.2R3-S1. PR1461831

  • RED drop on interface, no congestion. PR1470619

Class of Service (CoS)

  • CoS is incorrectly applied on Packet Forwarding Engine, leading to egress traffic drop. PR1329141

  • When the forwarding-class is configured under firewall policer, the dfwd might crash. PR1436894

Interfaces and Chassis

  • Upgrading to Junos OS Release 17.4R1 results in generating cfmd process core file. PR1425804

Layer 2 Ethernet Services

  • DHCP request might get dropped in a DHCP relay scenario. PR1435039

Platform and Infrastructure

  • The REST API process becomes non-responsive when a number of requests come with a high rate. PR1449987

Routing Protocols

  • On ACX Series platforms, the loopback address exported into another VRF instance might not work. PR1449410

  • MPLS LDP might still use the stale MAC of the neighbor even after the LDP neighbor's MAC changes. PR1451217

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

Resolved Issues:18.4R2

Class of Service (CoS)

  • Error message STUCK_BUFF : port_sp not empty for port 35 sp 1 pkts:1 is seen. PR1346452

General Routing

  • SNMP MIB walk/get/set on jnxDomCurrentTable and jnxDomNotifications might fail on ACX Series platforms. PR1076943

  • The 1-Gigabit copper module interface shows Link-mode: Half-duplex on QFX10000 line platforms. PR1286709

  • On an ACX Series ring topology, after link between ACX Series and MX Series flap, VPLS RI on PE (MX) have no MAC of CE over l2 circuit. PR1360967

  • On ACX5000, fpc0 (acx_rt_ip_uc_lpm_install:LPM route add failed) Reason : Invalid parameter error is seen after configuring lpm-profile. PR1365034

  • On ACX5448, LIBCOS_COS_TVP_FC_INFO_NOT_FOUND: Forwarding-class information not specified prints while commit on configuration prompt. PR1376665

  • On ACX5448 channelized ET interface of 25-Gigabit interface might not come up after chassis-control restart. PR1379288

  • The L2 circuit might stop forwarding traffic when one core interface flap. PR1381487

  • On ACX 5448, 100-Gigabit link FEC enabled by default on 100-Gigabit LR4. PR1389518

  • On ACX Series platforms the forwarding-option dhcp-relay forward-only configuration statement stops working and the DHCP packets are dropped. PR1392261

  • On ACX Series, MTU is not properly applied and output of ping mpls l2circuit sweep is giving lower values than expected. PR1393947

  • On ACX5048, the rpm rfc2544-benchmarking test fails to start. PR1395730

  • Error message ACX_PFE_ERROR: dnx_cfm_bd_endpoint_create: Failed to destroy the remote endpoint, Endpoint id 0x2001001, Entry not found is logged. PR1397878

  • CFM adjacency is not going down with distinct intervals. PR1397883

  • Error message ACX_ASIC_PROGRAMMING_ERROR: dnx_cfm_bd_endpoint_create: Failed to create the local endpoint Invalid parameter been logged on peer node. PR1397951

  • Output packet error Count incrementing on 100GE, 40GE ports. PR1398270

  • High jsd or na-grpcd CPU usage might be seen even JET or JTI is not used. PR1398398

  • Dynamic tunnels are not supported on ACX Series routers. PR1398729

  • FPC might crash after offline/online MIC-3D-16CHE1-T1-CE-H. PR1402563

  • VLAN tagged traffic arriving on VPLS interface might get dropped. PR1402626

  • The ot/et interface is not created when invalid speed is configured. PR1403546

  • On ACX 5448, TrTCM policer configuration parameters are as per RFC4115. PR1405798

  • show services inline stateful-firewall flow or show services inline stateful-firewall flow extensiveccommand might cause the memory leak. PR1408982

  • ACX Series routers drops DNS responses which contain an underscore. PR1410062

  • The aggregated Ethernet interface Twamp history statistics verification on client is not as expected getting Request Timed Out error. PR1411344

  • VPLS traffic might stop across ACX5000 with the aggregated Ethernet interface. PR1412042

  • Junos PCC might reject PCUpdate/PCCreate message if there is metric type other than type 2. PR1412659

  • Number of inet-arp policers implemented on ACX 5000 is increased from 16 to 64. PR1413807

  • The swap memory does not get initialized on boot on ACX5048. PR1415898

  • Commit error while configuring firewall with term having log/syslog and accept actions. PR1417377

  • On ACX5448 routers, BFD timer values are not as per the configured 900ms with multiplier 3, its showing 6.000 with multiplier 3 instead for most of the sessions. PR1418680

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

  • Copying images from WAN interface to Routing Engine of ACX5448 takes long time. PR1422544

  • The FPC or fxpc crash might be observed on an ACX Series platforms. PR1427362

Interfaces and Chassis

  • Upgrading to Junos OS Release 17.4R1 results in generating cfmd process core file. PR1425804


  • MPLS ingress LSP's for LDP link protection are not coming up after disabling or enabling MPLS. PR1432138

Services Applications

  • The spd might crash when any-ip is configured in the 'from' clause of the NAT rule with the static translation type. PR1391928

Resolved Issues:18.4R1

General Routing

  • Incorrect packet statistics are reported in the ifHCInUcastPkts OID. PR1306656

  • ACX Series routers support from dual-tagged through untagged packets Layer 3 traffic. PR1307666

  • Port xe-0/3/0 did not come up. PR1328207

  • ACX Series routers are incorrectly allowing to configure higher values in burst-size-limit than what is supported by the hardware. PR1361482

  • ACX Series routers autonegotiation shows incorrect values for link-partner when using SFP-LH or SFP-SX transceivers in combo-ports or SFP ports. PR1362490

  • FEC PM error counters are accumulated instead of resetting after bin rollover. PR1363270

  • VPLS with vlan-id-list is not working properly in some releases when the link between a PE device and a CE device is an aggregated Ethernet interface with a single member link and child physical interface flap. PR1365894

  • The commit or commit check operation might fail because of the error cannot have lsp-cleanup-timer without lsp-provisioning. PR1368992

  • The fxpc might crash after an interface is changed on ACX5000 routers. PR1378155

  • Timestamp is incorrect for BER statistics after clearing. PR1386253

  • The request chassis beacon CLI command is not working for pic-slot 1 (that is, CFP2 ports). PR1386711

  • Certain builds of Junos OS do not allow you to upgrade or commit configuration changes when the SI service interface is used. PR1393729

  • ACX Series routers does not support physical-interface-filter semantic in egress direction for any filters. It supports interface-specific command only. PR1395362

  • High jsd or na-grpcd CPU usage might be seen when JET or JTI is not used. PR1398398

Platform and Infrastructure

  • On Junos OS, the next-hop index allocation fails and private index space get exhausted through incoming ARP requests to management interface (CVE-2018-0063). PR1360039

Documentation Updates

There are no errata or changes in Junos OS Release 18.4R3 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 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

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