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Known Limitations


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


  • EVPN service over uncolored scaled SR-TE is not supported. PR1499719

General Routing

  • Subscriber access facing CPU’s utilization of FPC remains 100 percent for 56 minutes after making changes to the service firewall filter configuration. PR1447003

  • On the MPC11E line card, the following error messages are seen when the line card is online: i2c transaction error (0x00000002). PR1457655

  • On the MX10003 routers, during ISSU from Junos OS Release 18.2X75-D430 to 20.3R1, the link flaps and traffic drops for MACsec TIC, PR1514694

  • The MPC11E line card might take additional time to come during the movement from one GNF to another GNF. PR1469729

  • On the MX10003 or MX204 routers, BFD or LACP might flap during the BGP convergence. PR1472587

  • PSX.0 changes that have active subscribers causes the line card to crash. PR1486665

  • Observing traffic drop of around 2.5 seconds on switchover from primary physical interface to backup FTI interface with scaled routes. PR1490070

  • During MBB, a few packets may be dropped while bringing up the FTI logical interface, which is the primary interface. PR1507779

  • Memory leak observed in the JSD process with one or more collector(s) connecting and disconnecting during streaming of the telemetry data. PR1512296

Interfaces and Chassis

  • Traffic stalled and standby PWS states are not updated on changing to vlan-bridge encapsulation and then back to vlan-circuit-cross-connect. PR1503102


  • On the MX480 router, the following error message is observed: FPC Resource Monitor: FPC 0 and 1 Heap Memory has crossed free memory watermark of 20. PR1513436

Network Management and Monitoring

  • SNMP Support for RIB Sharding and Threading (MX Series)—In Junos OS Release 20.3R1, when you enable RIB Sharding, BGP MIB and L3VPN MIB don’t support the below attributes:

    Unsupported attributes for BGP MIB

    • bgp4PathAttrPeer

    • bgp4PathAttrIpAddrPrefixLen

    • bgp4PathAttrIpAddrPrefix

    • bgp4PathAttrOrigin

    • bgp4PathAttrASPathSegment

    • bgp4PathAttrNextHop

    • bgp4PathAttrMultiExitDisc

    • bgp4PathAttrLocalPref

    • bgp4PathAttrAtomicAggregate

    • bgp4PathAttrAggregatorAS

    • bgp4PathAttrAggregatorAddr

    • bgp4PathAttrCalcLocalPref

    • bgp4PathAttrBest

    • bgp4PathAttrUnknown

    Unsupported attributes for L3VPN MIB

    • mplsL3VpnVrfRteInetCidrDestType

    • mplsL3VpnVrfRteInetCidrDest

    • mplsL3VpnVrfRteInetCidrPfxLen

    • mplsL3VpnVrfRteInetCidrPolicy

    • mplsL3VpnVrfRteInetCidrNHopType

    • mplsL3VpnVrfRteInetCidrNextHop

    • mplsL3VpnVrfRteInetCidrIfIndex

    • mplsL3VpnVrfRteInetCidrType

    • mplsL3VpnVrfRteInetCidrProto

    • mplsL3VpnVrfRteInetCidrAge

    • mplsL3VpnVrfRteInetCidrNextHopAS

    • mplsL3VpnVrfRteInetCidrMetric

    • mplsL3VpnVrfRteXCPointer

    • mplsL3VpnVrfRteInetCidrStatus

Platform and Infrastructure

  • PIM join message (S,G) might not be created after GRES. PR1457166

  • Unknown unicast filter applied in the EVPN routing instance blocks unexpected traffic. PR1472511

  • Even after subscribing to /junos/system/linecard/firewall/,starting the GNMI decoder and performing negative interface triggers the subscription and TCP session remains. PR1477790

  • EVPN aliasing does not work over a SR-TE underlay. PR1504412

Routing Protocols

  • Commit check fails when rib-sharding is configured with these statements:

    • routing-instances <name> routing-options multipath

    • routing-instances <name> routing-options policy-multipath

    • routing-instances <name> protocols mvpn.

Subscriber Management and Services

  • Subscriber management and services are not supported on MPC10 or MPC11 line cards when you use these cards for subscriber access. MPC10 and MPC11 line cards support subscriber management and services only when you use these cards for uplink purposes to the core.