Cisco IOS XR software is a distributed operating system designed for continuous system operation
combined with service flexibility and high performance.

Cisco IOS XR software provides the following features and benefits:

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IP and Routing—Supports a wide range of IPv4 and IPv6 services, and routing protocols; such as
Border Gateway Protocol (BGP), Intermediate System-to-Intermediate System (IS-IS), Open
Shortest Path First (OSPF), IP Multicast, Routing Policy Language (RPL), and Hot Standby Router
Protocol (HSRP)/Virtual Router Redundancy Protocol features (VRRP).

•

MPLS—Supports Multiprotocol Label Switching (MPLS) protocols such as Traffic Engineering
(TE), Resource Reservation Protocol (RSVP), and Label Distribution Protocol (LDP).

•

Multicast—Provides comprehensive IP Multicast software including Source Specific Multicast
(SSM). The Cisco CRS-1 platform supports Bidirectional Protocol Independent Multicast
(BIDIR-PIM).

•

Quality of service (QoS)—Supports a rich QoS mechanisms including policing, marking, queuing,
dropping, and shaping. Additionally the operating systems support Modular QoS CLI (MQC). MQC
is used to configure various QoS features on various Cisco platforms.

•

Manageability—Provides industry-standard management interfaces including modular
command-line interface (CLI), Simple Network Management Protocol (SNMP), and native
Extensible Markup Language (XML) interfaces.

•

Security—Provides comprehensive network security features including access control lists (ACLs),
routing authentications, AAA/TACACS+, Secure Shell (SSH), SNMPv3, and leading Routing
Policy Language (RPL) support. Control-plane protections integrated into line card ASICs include
Generalized TTL Security Mechanism (GTSM), RFC 3682, and dynamic control plane protection.