This feature allows you to stream MDT data—both cadence-driven telemetry (CDT) and event-driven telemetry (EDT) data—for changes detected during install operation. After the install operation is complete, this functionality streams telemetry data such as the GISO label, image version, the status of install operation, and potential information about rectifying the installation process for all the active and committed packages.

With this feature, you can stream telemetry data from the following sensor paths:

Cisco-IOS-XR-install-oper:install/request

Cisco-IOS-XR-install-oper:install/packages/committed/summary

Cisco-IOS-XR-install-oper:install/packages/active/summary

Cisco-IOS-XR-install-oper:install/version

You can determine whether a software version can be upgraded or downgraded to another version using this functionality. Before an actual upgrade or downgrade process, you can also view the hardware or software limitations that could cause the upgrade or downgrade to fail. This feature helps you plan successful software upgrades or downgrades.

This feature introduces the show install upgrade-matrix command.

This feature streams telemetry data for cached generic counters using a TARGET_DEFINED subscription. This subscription ensures that any change to the cache streams the latest data to the collector as an event-driven telemetry notification.

This feature introduces support for the following sensor path:

Cisco-IOS-XR-infra-statsd-oper:infra-

statistics/interfaces/interface/cache/generic-counters

This feature is now supported on routers that have Cisco NC57 line cards installed and operate in native and compatibiltiy mode.

The feature advertises a best external route to its internal peers as a backup route. The backup route is stored in the RIB and Cisco Express Forwarding. If the primary path fails, the BGP PIC functionality enables the best external path to take over, enabling faster restoration of connectivity.

This feature is now supported on routers that have Cisco NC57 line cards installed and operate in native and compatibiltiy mode.

This feature enables recreate the essence of OSPF Cost Fallback feature for LAG bundles for directly connected BGP sessions from a PE to a core router.

This feature is now supported on routers that have Cisco NC57 line cards installed and operate in native and compatibiltiy mode.

This feature enables BGP PIC backup path when the primary path is a static route with the next hop as an IP Address.

This feature uses entropy labels to load balance BGP LU traffic across the SP network. Entropy labels are additional labels that are added on the ingress Label Switching Router.

Since the core routers load balance labelled traffic flows using entropy labels, deep inspection of packets isn't necessary for transit routers, thus providing better load balancing and preventing congestion.

This feature is supported on Cisco NCS 5700 series routers and Cisco NCS 5500 series routers when configured in native mode (using the hw-module profile npu native-mode-enable command), and it supports RFC 6790 (The Use of Entropy Labels in MPLS Forwarding) specification.

Use this feature to collect logs that contain debug information for ltraces and tech-support data. These logs aid in troubleshooting whenever the scripts are not working as expected.

This feature introduces the show tech-support script command.

This feature lets you update automation scripts across routers by accessing the master script from a remote site. This eases script management, where you make changes to the master script and then copy it to routers where it is deployed.

This feature introduces the auto-update keyword in the script exec command.

This feature allows local containers and scripts on the router to establish gRPC connections over UNIX domain sockets. These sockets provide better inter-process communication eliminating the need to manage passwords for local communications. Configuring communication over UNIX domain sockets also gives you better control of permissions and security because UNIX file permissions come into force.

This feature introduces the grpc local-connection command.

This feature is supported on Cisco Network Convergence System 5700 Series routers and routers with the Cisco NC57 line cards operating in native mode. This feature extends MAID functionality to support the flexible format for hardware offloaded MEPs. This removes the restrictions on the type of MAID supported for sessions with less than 1 minute time intervals.

To enable the feature in native mode, run the hw-module profile oam 48byte-cfm-maid-enable command in the System Admin Config mode, and reload the router.

A Global Navigation Satellite System (GNSS) receiver receives radio signals from GNSS satellites and decodes the information from multiple satellites to determine its distance from each satellite. Based on this data, the GNSS receiver identifies the location of each satellite.

This feature is supported on the following variants of Cisco Network Convergence System 5700 Series fixed chassis:

• NCS-57B1-6D24-SYS

• NCS-57B1-5DSE-SYS

For more information about the Cisco NCS 5700 series fixed chassis, see the Cisco NCS-57B1 Fixed Chassis Data Sheet.

This release introduces support for Optical Network Transport (OTN) on NC55-MPA-12T-S Modular Port Adapter (MPA) on the following Cisco NCS 5500 Series Line cards:

• NCS-55A2-MOD-S

• NCS-55A2-MOD-SE-S

• NCS-55A2-MOD-HX-S

• NCS-55A2-MOD-SE-H-S

• NCS-55A2-MOD-HD-S

OTN is a superior technology that bridges the gap between next-generation IP and legacy time-division multiplexing (TDM) networks by acting as a converged transport layer for newer packet-based and existing TDM services. OTN provides robust transport services that leverage many benefits of SONET/SDH, such as resiliency and performance monitoring, while adding enhanced multi-rate capabilities in packet traffic.

The Cisco NCS 5500 Series Routers support Ethernet, SONET/SDH, and OTN client interfaces with data rates from 1 to 10 Gigabits per second.

To enable OTN, use the pm otn report enable command in the otu2e or odu2e mode.

With this feature, you can disable generating the ICMP unreachable message when any traffic packet drops due to a deny ACE. This feature works in the global configuration mode and avoids the cumbersome task of disabling the ICMP unreachable per ACE. Disabling ICMP unreachable message in the router saves your network bandwidth. This feature applies to IPv4, IPv6, and MPLS enabled traffic.

Commands modified:

• ipv4 access-list

• ipv6 access-list

With this feature, you can configure the IPv6 Extended Access Lists with Fragment Control. This feature allows more granularity of control over non-initial fragments of an incoming IPv6 packet. It also adds an extra layer of protection against Denial of Service ( DoS) attacks by filtering the incoming fragments of the IPv6 packet in a network.

This feature is now supported on Cisco NCS 5700 Series Fixed Port Routers and the Cisco NCS 5500 Series Routers that have the Cisco NC57 line cards installed and operating in the native mode.

Commands modified:

• is-fragment

• first-fragment

This feature is supported on routers that have Cisco NC57 line cards installed and operate in native mode.

This feature allows you to extend the physical links to have VLANs (ACs) that act as Ethernet Virtual Circuits (EVCs). Many such EVCs can be aggregated on a single main interface called Virtual Ethernet Segment (vES). The main interface aggregates many vESs and creates a group to identify these vESs. This mechanism helps to minimize service disruption by mass withdrawal for main peering at the vES level.

This feature is now supported on routers that have Cisco NC57 line cards installed and operate in compatibility mode.

L2 Control Protocols (L2CP) tunneling helps initiate control packets from a local CE (customer-edge) device to a remote CE device.

This feature is now supported on routers that have Cisco NC57 line cards installed and operate in native mode.

The EVPN E-Tree feature provides a rooted-multipoint Ethernet service over MPLS core. The E-Tree service enables you to define attachment circuits (ACs) as either a root site or a leaf site, which helps in load balancing and avoiding loops in a network.

The Ethernet Data Plane Loopback feature allows you to run loopback tests to test the connectivity and quality of connections through a Layer 2 cloud. The Ethernet Data Plane Loopback supports the following services on routers that have the Cisco NC57 line cards installed and operate in the native mode:

• BGP-VPLS

• EVPN-ELAN

• EVPN-VPWS

For Traffic Engineering, VPLS traffic can be sent using MPLS-TE with RSVP or SR-TE.

Resource Reservation Protocol (RSVP) is a signaling protocol that enables systems to request resource reservations from the network. MPLS Traffic Engineering (MPLS-TE) learns the topology and resources available in a network and then maps traffic flows to particular paths, based on resource requirements and network resources such as bandwidth. MPLS-TE uses RSVP to signal LSPs.

Segment routing for traffic engineering (SR-TE) uses a “policy” to steer traffic through the network.

For Traffic Engineering, VPLS traffic can be sent using MPLS-TE with RSVP or SR-TE.

Resource Reservation Protocol (RSVP) is a signaling protocol that enables systems to request resource reservations from the network. MPLS Traffic Engineering (MPLS-TE) learns the topology and resources available in a network and then maps traffic flows to particular paths, based on resource requirements and network resources such as bandwidth. MPLS-TE uses RSVP to signal LSPs.

Segment routing for traffic engineering (SR-TE) uses a “policy” to steer traffic through the network.

This feature is now supported on routers that have Cisco NC57 line cards installed and operate in native mode.

BGP VPWS services support CFM continuity check, ITU-T Y.1731 compliant Delay Measurement Message (DMM) and Synthetic Loss Measurement (SLM) functions.

This feature is now supported on routers that have Cisco NC57 line cards installed and operate in native mode.

EVPN ELAN services support CFM continuity check, ITU-T Y.1731 compliant Delay Measurement Message (DMM) and Synthetic Loss Measurement (SLM) functions. This feature is supported only on single-homed EVPN ELAN.

This feature is now supported on routers that have Cisco NC57 line cards installed and operate in native mode.

EVPN VPWS services support CFM continuity check, ITU-T Y.1731 compliant Delay Measurement Message (DMM) and Synthetic Loss Measurement (SLM) functions. This feature is supported only on single-homed EVPN VPWS.

This release introduces support for Ethernet ACLs on NC57 line cards. This feature allows Layer 2 network traffic filtering via MAC addresses.

For more information, see L2VPN and Ethernet Services Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 7.5.x.

This feature introduces bandwidth protection functions for auto-tunnel backups, such as signaled bandwidth, bandwidth protection, and soft-preemption. These functions provide better bandwidth usage and prevent traffic congestion and traffic loss.

In earlier releases, auto-tunnel backups provided only link protection and node protection. Backup tunnels were signaled with zero bandwidth, causing traffic congestion when FRR went active.

This feature introduces the following commands and keywords:

• bandwidth-protection maximum-aggregate

• signalled-bandwidth

• soft-preemption

This feature is now supported on routers that have the Cisco NC57 line cards installed and operate in native and compatible modes.

MVPN profile 0 uses GRE tunnels to securely transmit multicast traffic between the PE routers.

This feature gives you the flexibility to customize the metrics that IGP uses to route traffic for MLDP tunnels. With this feature, your router can generate two multicast streams for the same feed, thus ensuring low latency and high availability of multicast traffic.

This feature introduces the flex-algo keyword.

This feature is now supported on routers that have the Cisco NC57 line cards installed and operate in native and compatible modes.

IPv6 multicast supports multiple sources for a single multicast group.

This feature is now supported on routers that have the Cisco NC57 line cards installed and operate in native and compatible modes.

Routers use MLD to learn whether members of a group are present on their directly attached subnets over BVI interface.

This feature is now supported on routers that have the Cisco NC57 line cards installed and operate in native and compatible modes.

Multicast over GRE allows encapsulation of multicast packets using GRE tunnels, thereby enabling transport of multicast packets securely between source and destination routers located in different IP clouds.

With this feature, MVPN profile 14 is now extended to support PIM SM mode for IPv4 and static RP.

PIM SM for MVPN is not supported on Cisco NC57 line cards.

This feature is now supported on routers that have the Cisco NC57 line cards installed and operate in native and compatible mode.

With this feature, the router can quickly switch traffic to a precomputed loop-free alternative (LFA) path by allocating a label to the incoming traffic. This minimizes the traffic loss ensuring fast convergence.

Using this feature, you can configure a multicast router interface to override the configuration specified in the local VRF table. When an IGMP client sends a join message to the multicast router, it performs a Reverse-path Forwarding (RPF) lookup for the IGMP join in the local VRF table. If the local VRF table does not have the information, the feature extends the lookup to the default (global) VRF table.

This ensures that the interface in a specific VRF table is part of the outgoing list of interfaces in the global routing table for a multicast route.

Sampled flow (sFlow) allows you to monitor real-time traffic in data networks that contain switches and routers. It uses the sampling mechanism in the sFlow agent software on routers to monitor traffic and to forward the sample data to the central data collector.

sFlow uses version 5 export format to forward sampled data.

Using this feature, you can match class maps to IPv4 and IPv6 destination addresses on Layer 2 networks. The Layer 2 interface service policy has the relevant class maps, actioning them for ingress QoS operations.

This feature provides you with an additional level of classification for aggregated customer traffic at your ingress, thus giving you granular control on traffic flows.

• match destination-address

• hw-module profile qos l2-match-dest-addr-v4v6

This feature gives you the option to assign the highest priority to IS-IS and Address Resolution Protocol (ARP) packets in transit. This feature is disabled by default.

The feature provides more flexibility in transit traffic management on a per-hop basis and also fine-tunes the traffic profile management for transit traffic.

This feature is now supported on routers that have the Cisco NC57 line cards installed and operate in native and compatible modes.

This feature introduces BFD support over VRRP interfaces.

This feature is now supported on routers that have the Cisco NC57 line cards installed and operate in native and compatible modes.

This feature feature enables you to configure IPv4 Multihop BFD on MPLS LDP and Segment Routing.

This feature allows the Flexible Algorithm definition to specify Shared Risk Link Groups (SRLGs) that the operator wants to exclude during the Flex-Algorithm path computation.

This allows the setup of disjoint paths between two or more Flex Algos by leveraging deployed SRLG configurations.

This feature provides the ability to assign a specific SRv6 locator for a given prefix or a set of prefixes (IPv4/IPv6 GRT, IPv4/IPv6 VPN).

The egress PE advertises the prefix with the specified locator. This allows for per-prefix steering into desired transport behaviors, such as Flex Algo.

This feature extends the current OSPF Flexible Algorithm functionality to support Flex-Algo Prefix Metric.

This feature introduces a Flexible Algorithm-specific prefix-metric in the OSPF prefix advertisement. The prefix-metric provides a way to compute the best end-to-end Flexible Algorithm optimized paths across multiple areas or domains.

The SR-PCE provides a north-bound HTTP-based API to allow communication between SR-PCE and external clients and applications. The Cisco Crosswork Optimization Engine is an application that leverages the SR-PCE.

This release adds support for the following:

• Stateful North-Bound API for Tree-SID using a subscription model

• SR-PCE continuous notifications of modified or deleted Tree-SIDs as they occur

This feature allows locally authenticated users—authenticated by the AAA server internal to the router—to run all XR VM commands even if a remote TACACS+ AAA server is not reachable for authorization. It prevents a complete router lockdown. The feature also prevents remotely authenticated users—authenticated using a remote AAA server (say, TACACS+ server)—from running any non-permitted commands on the router, and thus prevents misuse of user privileges.

This feature modifies the aaa authorization commands default command to include the local option for XR VM command authorization.

This feature enables users to optionally gate the Lawful Intercept (LI) enablement on their routers with network vendor's consent, using a consent-token. It also provides an optional package to disable the LI feature for the first time on their routers. This feature is in compliance with the latest ANSSI (Agence nationale de la sécurité des systèmes d'information) security standards.

Prior to this release, there was no gating for LI enablement on routers.

The associated command is:

• request consent-token

This release brings in parity between inband interfaces and management Ethernet interfaces with respect to the default behavior for network management traffic permissions. The feature provides a default configuration option to block the management traffic on management Ethernet interfaces when MPP is enabled. This feature thus enhances router-level security and provides more granularity in controlling management access to the router.

In earlier releases, all management traffic was allowed, by default, on the management Ethernet interfaces, even with MPP enabled.

This feature is supported on routers that have the Cisco NC57 line cards installed and operating in the native mode.

This feature introduces the enable-inband-behaviour command.

This feature securely stores local command accounting log files that you don't need to access regularly in a specified archive location. Archiving allows you to retain infrequently used log files for operational or regulatory requirements.

The associated commands are:

• logging file filename path pathname local-accounting

• logging archive

This feature lets you run a customized list of show commands and System Admin show commands from all core protocols such as BGP, MPLS, Segment Routing etc. You can also generate tech-support information that is useful for Cisco Technical Support representatives when troubleshooting a router.

This feature introduces the show tech support custom profile-name command.