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Routing Protocols

  • Support for SR-IOV virtualization (JRR200)—Starting in Junos OS Release 21.1R1, the JRR200 route reflector uses single-root I/O virtualization (SR-IOV) instead of full virtualization (emulated I/O) for network ports. SR-IOV helps to maximize the I/O throughput on the 10GbE SFP+ ports.

    SR-IOV improves:

    • BGP convergence in a scaled environment.
    • Throughput performance for BGP RIB sharding.

    [See BGP sharding overview, rib-sharding, and update-threading.]

  • IS-IS link delay measurement and advertising (MX Series)—Starting in Junos OS Release 21.1R1, you can measure and advertise various performance metrics in IP networks with scalability, by using several IS-IS probe messages. These metrics can then be used to make path-selection decisions based on network performance.

    [See How to Enable Link Delay Measurement and Advertising in IS-IS, delay-measurement, and delay-metric.]

  • Support for configuring multiple independent IGP instances of IS-IS (ACX Series, MX Series, and PTX Series)—Starting in Junos OS Release 21.1R1, you can configure and run multiple independent IGP instances of IS-IS simultaneously on a router.


    Junos OS does not support configuring the same logical interface in multiple IGP instances of IS-IS.

    [See How to Configure Multiple Independent IGP Instances of IS-IS.]

  • Support for IP forward backup path for BGP-LS peer SIDs (PTX Series)—Starting in Junos OS Release 21.1R1, you can configure an IP forward backup path that provides protection at the local node or the point of local repair for egress peer engineering. When the primary segment goes down, the packet is forwarded to the configured IP backup path. This IP forward backup path has local node significance only. BGP does not send the IP forward backup path information to the controller in its periodic BGP Link State (BGP-LS) updates. If you have configured both segment protection and IP forward backup path, then backup segment protection takes precedence over the IP forward backup path protection.

    To configure IP forward backup path for BGP-LS peer segments, include the egress-te-backup-ip-forward option at the [edit bgp egress-te–segment-set], [edit bgp group group-name egress-te-node-segment], and [edit bgp group group-name egress-te-segment adj] hierarchy levels.

    [See egress-te-set-segment, ,egress-te-node-segment, and egress-te-adj-segment.]

  • Support for BGP Auto-discovered Neighbor (MX Series, PTX1000, PTX10008, QFX5120-32C, QFX5200, QFX5210, and QFX10008)—Starting in Junos OS Release 21.1R1, we support BGP auto-discovered neighbors using IPv6 Neighbor Discovery Protocol (ND). With this feature, you can enable BGP to create peer neighbor sessions using link-local IPv6 addresses of directly connected neighbor devices. You need not specify remote or local neighbor IP addresses.

    To enable peering for a given interface or set of interfaces without specifying the local or remote neighbor addresses, configure the peer-auto-discovery statement at the [edit fabric protocols bgp group <name> dynamic-neighbor <name>] hierarchy level.

    [ See BGP Auto-Discovered Neighbors, and peer-auto-discovery.]