Smart Licensing is a cloud-based, software license management solution that enables you to automate time-consuming, manual licensing tasks. The solution allows you to easily track the status of your license and software usage trends.

Note	By default Smart Licensing is enabled. Only non-consumption model Smart Licensing is supported.

For information on configuring Smart Licensing, see the chapter Software Entitlement in the System Management Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x

BFD transparency feature enables Bidirectional Forwarding Detection (BFD) sessions between CEs connected over L2VPN network to come up seamlessly without BFD packets getting processed or dropped in the L2VPN Core.

For more information, see the Routing Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x.

Bridge Virtual Interfaces (BVIs) provide a bridge between the routing and bridging domains on a router. A BVI is configured with an IP address and operates as a regular routed interface. You can configure an ACL on a BVI to filter the traffic for the network that uses the interface.

To know how to configure an IPv4 egress ACL on a BVI, see the ACLs on Bridge Virtual Interfaces section in the IP Addresses and Services Configuration Guide for Cisco NCS 5500 Series Routers.

Most DoS (Denial of Service) attacks work by flooding the network with fragmented packets. By filtering the incoming fragments of the packet in a network, an extra layer of protection can be added against such attacks. You can configure an IPv4 ACL to match on the fragment type, and perform an appropriate action.

For information about configuring an IPv4 ACL to match by the various fragment types, see Configuring an IPv4 ACL to Match on Fragment Type section in the IP Addresses and Services Configuration Guide for Cisco NCS 5500 Series Routers. For information about the various fragment types to match on, see the following command pages in the IP Addresses and Services Command Reference for Cisco NCS 5500 Series Routers.

• dont-fragment

• is-fragment

• first-fragment

• last-fragment

IOS-XR implementation of IP-MIB now supports IPv4 statistics as per RFC4293. Refer to the SNMP OID Navigator for a list of new OIDs added for iPv4 statistics.

The feature adds the possibility to run an Integrated Intermediate System-to-Intermediate System (IS-IS) process in the context of a non-default VPN routing and forwarding (VRF). Both IPv4 and IPv6 are supported. The implementation is more suitable for VRF-lite scenarios.

For more information, see the Routing Configuration Guide for Cisco NCS 5000 Series Routers, IOS XR Release 6.3.x.

You can configure ACLs to match on the TTL value specified in the IPv4 or IPv6 header. You can specify the TTL match condition to be based on a single value, or multiple values. You can also rewrite the TTL value in the IPv4 or IPv6 header by using the set ttl command. TTL matching is supported only for ingress ACLs.

ACLs that are shared across interfaces and use the same TCAM space are known as shared ACLs. However, you can configure only 31 unique, shared ACLs. To configure more unique ACLs, ACL sharing must be disabled by using the interface-based command. By making the ACLs unique for an interface, you can configure more than 31 ACLs.

For information on configuring ACLs to match on TTL values and configuring unique ACLs, see the Configuring TTL Matching for IPv4 ACLs and Configuring TTL Matching for IPv6 ACLs sections in the IP Addresses and Services Configuration Guide for Cisco NCS 5500 Series Routers.

A binding segment is a local segment that identifies an SR-TE policy. Each SR-TE policy is associated with a binding segment ID (BSID). By default, a BSID is allocated automatically for each SR-TE policy when the SR-TE policy is instantiated.

The Explicit BSID feature allows you to request that the SR-TE policy uses a BSID value that you provide. Explicit BSIDs are allocated from the segment routing local block (SRLB) or the dynamic range of labels. You can also specify how the BSID allocation behaves if the BSID value is not available.

For more information on this feature, see the Configure SR-TE Policies chapter in the Segment Routing Configuration Guide for NCS 5500 Series Aggregation Services Routers.

BGP commit replace for neighbour groups feature allows you to move an autonomous system from a BGP neighbour to a BGP neighbour group in a single IOS-XR commit.

Conditional Marking of MPLS Experimental bits for L3VPN Traffic feature enables the user to configure the conditional marking of MPLS Experimental bits for L3VPN Traffic on the Provider Edge routers in the imposition direction.

For more information on this feature, see the Configuring Modular QoS Service Packet Classification chapter in the Modular QoS Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x

Bit Error Rate (BER) is a number of bit errors per unit time that determines the reliability of a link. The system supports BER on 10/40/100 GE interfaces. The system raises an alarm or brings down the TX of an interface once the error value crosses the configured threshold value.

Link fault signalling (LFS) is a physical layer protocol that enables communication on a link between Ethernet devices. When you configure a device on a network, the port can detect and report fault conditions on transmit and receive ports.

For more information, see the Interface and Hardware Component Configuration Guide for Cisco NCS 5500 Series Routers guide.

This feature provides tunable support for the dense wavelength-division multiplexing (DWDM) wavelengths of the DWDM-XFP-C module on the Cisco NCS 5500 Series Aggregation Services Routers. You can configure the DWDM ITU wavelengths by using the itu channel command in the interface configuration mode.

For more information, see the Interface and Hardware Component Configuration Guide for Cisco NCS 5500 Series Routers guide.

This features provides support for DWDM optics PID. The itu channel command ensures that the traffic continues to flow. The modules have the operating wavelengths according to ITU-T G.692 at 100GHz grids in C-band.

For more information, see the Interface and Hardware Component Configuration Guide for Cisco NCS 5500 Series Routers guide.

With the introduction of this feature, the system supports the IOS XR LLDP enablement over the Management Interfaces on Cisco NCS 5500. This feature requires support from SPIO as LLDP uses SPIO for both transmission and reception of the frames.

For more information, see the Using Data Models chapter in Programmability Configuration Guide for Cisco NCS 5500 Series Routers.

By using a bridge-group virtual interface (BVI), you can convert multiple interfaces as members of a common broadcast domain. MPLS static over BVI feature allows you to specify a BVI interface as nexthop while setting up a static label-switched path (LSP).

For more information about configuring MPLS static over BVI feature, see MPLS Configuration Guide for Cisco NCS 5500 Series Routers, Release 6.3.x.

LDP over MPLS-TE feature combines the benefits of both LDP and RSVP protocols which are used to set up LSPs. While LDP is easy to configure, RSVP has traffic engineering capabilities which help to avoid traffic congestions. In LDP over MPLS-TE, an LDP signalled label-switched path (LSP) runs through a TE tunnel established using RSVP-TE.

For more information about configuring LDP over MPLS-TE feature, see MPLS Configuration Guide for Cisco NCS 5500 Series Routers, Release 6.3.x.

Path protection provides an end-to-end failure recovery mechanism for MPLS-TE tunnels. A secondary Label Switched Path (LSP) is established, in advance, to provide failure protection for the protected LSP that is carrying a tunnel's TE traffic. When there is a failure on the protected LSP, the source router immediately enables the secondary LSP to temporarily carry the tunnel's traffic.

For more information about configuring MPLS-TE path protection, see MPLS Configuration Guide for Cisco NCS 5500 Series Routers, Release 6.3.x.

BGP communities provides a way to group destinations and apply routing decisions such as acceptance, rejection, preference, or redistribution on a group of destinations using community attributes. BGP community attributes are variable length attributes consisting of a set of one or more 4-byte values which are split into two parts of 16 bits to represent AS number and a locally defined value. BGP large community is a 12 byte optional attribute which can accommodate 4 byte ASNs which cannot be accommodated by the BGP community or the BGP extended community.

For more information about configuring BGP large community feature, see Routing Configuration Guide for Cisco NCS 5500 Series Routers .

L2VPN VPLS or VPWS over SR-TE Preferred Path feature allows you to set the preferred path between the two end-points for L2VPN Virtual Private LAN Service (VPLS) or Virtual Private Wire Service (VPWS) using SR-TE policy.

For more information on this feature, see the L2VPN Preferred Path over Segment Routing for Traffic Engineering Policy chapter in the L2VPN and Ethernet Services Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.2.

The MPLS L3VPN Services using Segment Routing feature allows you to achieve better resilience and convergence for the network traffic, by transporting MPLS L3VPN services using Segment Routing (SR), instead of MPLS LDP. Segment routing can be directly applied to the MPLS architecture without changing the forwarding plane.

For more information on this feature, see the Implementing MPLS Layer 3 VPNs chapter in the L3VPN Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.2.

A DHCPv6 relay agent is a host that forwards DHCP packets between clients and servers that do not reside on a shared physical subnet. Relay agent forwarding is distinct from the normal forwarding of an IP router where IP datagrams are switched between networks transparently.

DHCP clients use User Datagram Protocol (UDP) broadcasts to send DHCP DISCOVER messages when they lack information about the network to which they belong.

If a client is on a network segment that does not include a server, a relay agent is needed on that network segment to ensure that DHCP packets reach the servers on another network segment. UDP broadcast packets are not forwarded, because most routers are not configured to forward broadcast traffic. You can configure a DHCPv6 relay agent to forward DHCP packets to a remote server by configuring a DHCPv6 relay profile and configure one or more helper addresses in it. You can assign the profile to an interface or a VRF.

For more information, see IP Addresses and Services Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x.

BGP dynamic neighbor support allows BGP peering to a group of remote neighbors that are defined by a range of IP addresses. Each range can be configured as a subnet IP address.

In larger BGP networks, implementing BGP dynamic neighbors can reduce the amount and complexity of CLI configuration and save CPU and memory usage. Both IPv4 and IPv6 peering are supported.

The BGP dynamic neighbor authentication support enhances security by enabling authentication while forming BGP dynamic neighbors.

For more information, see BGP Dynamic Neighbors chapter of the BGP Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x.

Fallback is a session recovery mechanism when primary PSK fails to bring up secured MKA session. It ensures that a PSK is always available to perform MACSec encryption and decryption.

• In CAK rollover of primary keys, if latest active keys are mismatched, system performs a hitless rollover from current active key to fallback key, provided the fallback keys match.

• If a session is up with fallback, and primary latest active key configuration mismatches are rectified between peers, system performs a hitless rollover from fallback to primary latest active key.

For more information, see System Security Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x.

Management Plane Protection (MPP) provides a mechanism for securing management traffic on the router. Without MPP, if the service is enabled, the Cisco IOS XR allows the service traffic to pass through any interface with a network address.

MPP configuration for third-party application (TPA) enables to filter the traffic of TPA component, for example, gRPC component. The addition of gRPC component controls the management protocol traffic and supports the management protocols for the TPA, for example, gRPC. It also helps to control the gRPC application and filter the gRPC traffic through MPP configuration.

For more information, see MPP for Third Party Applications chapter of the System Security Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x.

MACSec data delay protection allows MKA participants to ensure that the data frames protected by MACSec are not delayed by more than 2 seconds. Each SecY uses MKA to communicate the lowest packet number (PN) used for transmission with the Secure Association Key (SAK) within two seconds. Traffic delayed longer than 2 seconds are rejected by the interfaces enabled with delay protection.

This provides additional security in preventing any man-in-the-middle attack (MITM) or replay attack.

For more information, see Creating a User-Defined MACsec Policy section of the Configure MACSec Chapter of the System Security Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x.

BGP Labeled Unicast Multiple Label Stack feature enables the user to make the XR router receive and advertise BGP LU updates with a stack of one or more labels associated with the encoded prefix.

This feature provides the ability for a controller to push a multiple label stack through BGP labeled unicast session onto the headend.

For information about configuring BGP Labeled Unicast with Multiple Label Stack feature, see the BGP Configuration Guide for Cisco NCS 5500 Series Routers.

BPDU Transparency with MACSec feature enables you to create tunnel between a source customer edges (CE) device and destination CE devices and use this tunnel to carry traffic between these two CEs.

For more information on this feature, see the L2VPN and Ethernet Services Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.2.

Some topologies (for example the commonly used ring-based topology) require protection that is not afforded by Loop-Free Alternate (LFA) Fast Reroute (FRR) alone. In such cases, use the Label Distribution Protocol (LDP)-based FRR Remote LFA feature where IGPs compute non-directly connected neighbor, which are more than one hop away, as LFA backup path to protect the given prefix's primary path. The LDP sets up labeled backup LSP with the remote next-hop for the protected prefix. LDP also sets up another transport LSP to tunnel traffic to remote next-hop without exposing the LFA backup label as learnt from remote node.

For information about configuring Fast Reroute Remote Loop-Free Alternate feature, see the Routing Configuration Guide for Cisco NCS 5500 Series Routers.

Static LSP next hop resolve with recursive prefix feature supports resolution of recursive routes for static LSPs. This feature enables you to specify a next-hop which is not directly connected for a static LSP destination.

For more information about configuring static LSP next hop resolve with recursive feature, see MPLS Configuration Guide for Cisco NCS 5500 Series Routers .

Cisco IOS XR supports RPM signing and signature verification for Cisco IOS XR RPM packages in the ISO and upgrade images. All RPM packages in the Cisco IOS XR ISO and upgrade images are signed to ensure cryptographic integrity and authenticity. This guarantees that the RPM packages have not been tampered with and the RPM packages are from Cisco IOS XR. The private key, used for signing the RPM packages, is created and securely maintained by Cisco.

Cisco IOS XR supports Network-Instance, LLDP, and ISIS Open Config Models. These models have YANG models defined for configuration and operational data.

For more information about YANG data models and configuration, see Using Data Models chapter in Programmability Configuration Guide for Cisco NCS 5500 Series.

Internet Protocol Flow Information Export (IPFIX) is an IETF standard export protocol (RFC 7011) for sending IP flow information. Cisco NCS 5500 Router supports IPFIX 315 format to export flow information. IPFIX 315 format facilitates sending ‘n’ octets frame information starting from ethernet header till trasport header of the traffic flow over the network. IPFIX 315 supports sending variable size packet record with variable payload information such as IPv4, IPv6, MPLS, and Nested packets like OuterIP-GRE-InnerIP etc. The process includes sampling and exporting the traffic flow information. Along with the ethernet frame information, IPFIX 315 format exports information of incoming and outgoing interface of the sampled packet.

For information on configuring IPFIX 315, see Netflow Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x.

Golden ISO (GISO) is a customized installable image. GISO supports booting from PXE and USB.

For information about installing Golden ISO and booting options, see Customize Installation using Golden ISO chapter in System Setup and Software Installation Guide for Cisco NCS 5500 Series Routers.

Link Layer Discovery Protocol (LLDP) YANG model supports configuring event-driven telemetry.

For an example about configuring event-driven telemetry for LLDP, see Configure Model-driven Telemetry chapter in Telemetry Configuration Guide for Cisco NCS 5500 Series Routers .

The IPv4 Multihop BFD feature provides sub-second forwarding failure detection for a destination more than one hop, and up to 255 hops, away. The bfd multihop ttl-drop-threshold command can be used to drop BFD packets coming from neighbors exceeding a certain number of hops. BFD multihop is supported on all currently supported media-type for BFD singlehop.

. For more information on the IPv4 Multihop BFD feature, see the Routing Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.2.

EVPN VPWS over SR-TE Preferred Path feature allows you to set the preferred path between the two end-points for EVPN VPWS pseudowire (PW) using SR-TE policy.

For more information on this feature, see the L2VPN Preferred Path over Segment Routing for Traffic Engineering Policy chapter in the L2VPN and Ethernet Services Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.2.

EVPN Multiple Services per Ethernet Segment feature allows you to configure multiple services over single Ethernet Segment (ES). Instead of configuring multiple services over multiple ES, you can configure multiple services over a single ES. With this feature you can optimize the use of resources, especially bandwidth and reduce the cost of hardware.

For more information on this feature, see the EVPN Features chapter in the L2VPN and Ethernet Services Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.2.

EVPN Support for V6 Hosts with Mobility feature enables you to provide EVPN IPv6 service over IPv4-MPLS core network. This feature supports all-active multihoming and virtual machine (VM) or host move.

For more information on this feature, see the Configure EVPN IRB chapter in the L2VPN and Ethernet Services Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.2.

The EVPN VPWS On-Demand Next Hop with SR-TE feature enables you to fetch the best path to send traffic from the source to destination in a point-to-point service using IOS XR Traffic Controller (XTC).

For more information on this feature, see the L2VPN Preferred Path over Segment Routing for Traffic Engineering Policy chapter in the L2VPN and Ethernet Services Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.2.

The BFD Support for Multicast (PIM) feature, also known as PIM BFD, registers PIM as a client of BFD. PIM can then utilize BFD to initiate a session with an adjacent PIM node to support BFD's fast adjacency failure detection in the protocol layer. PIM registers with BFD. When PIM BFD is enabled, BFD notifies PIM about failures.

For more information about configuring PIM BFD feature, see Routing Configuration Guide for Cisco NCS 5500 Series Routers, Release 6.3.x.

The support for PIM on Bundle-Ethernet subinterface is introduced in this release.

IPv4 BFD for BGP over Bundle Interface feature, also known as Bidirectional Forwarding Detection (BFD) over Logical Bundle feature implements and deploys BFD over bundle interfaces based on RFC 5880. The BFD over Logical Bundle (BLB) feature replaces the BVLAN feature and resolves certain interoperability issues with other platforms that run BFD over bundle interface in pure RFC5880 fashion.

For more information on this feature, see the Routing Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.2.

Support has been provided for IPv6 egress ACLs on gigabit ethernet and bundle interfaces. To know more about the configuration prerequisites and steps, see Configuring IPv6 ACLs in the IP Addresses and Services Configuration Guide for Cisco NCS 5500 Series Routers.

Caveats describe unexpected behavior in Cisco IOS XR Software releases.