Specifications

Implementing OSPF on Cisco IOS XR Software
Information About Implementing OSPF on Cisco IOS XR Software
RC-223
Cisco IOS XR Routing Configuration Guide
Information About Implementing OSPF on Cisco IOS XR
Software
To implement OSPF you need to understand the following concepts:
• OSPF Functional Overview, page RC-223
• Key Features Supported in the Cisco IOS XR OSPF Implementation, page RC-224
• Comparison of Cisco IOS XR OSPFv3 and OSPFv2, page RC-225
• OSPF Hierarchical CLI and CLI Inheritance, page RC-225
• OSPF Routing Components, page RC-226
• OSPF Process and Router ID, page RC-229
• Supported OSPF Network Types, page RC-229
• Route Authentication Methods for OSPF, page RC-230
• Neighbors and Adjacency for OSPF, page RC-231
• Designated Router (DR) for OSPF, page RC-231
• Default Route for OSPF, page RC-231
• Link-State Advertisement Types for OSPF Version 2, page RC-231
• Link-State Advertisement Types for OSPFv3, page RC-232
• Virtual Link and Transit Area for OSPF, page RC-233
• Route Redistribution for OSPF, page RC-234
• OSPF Shortest Path First Throttling, page RC-234
• Nonstop Forwarding for OSPF Version 2, page RC-235
• Graceful Restart for OSPFv3, page RC-236
• Multicast-Intact Support for OSPF, page RC-238
• Load Balancing in OSPF Version 2 and OSPFv3, page RC-239
• Multi-Area Adjacency for OSPF Version 2, page RC-239
• Label Distribution Protocol IGP Auto-configuration for OSPF, page RC-240
• OSPF Authentication Message Digest Management, page RC-240
• GTSM TTL Security Mechanism for OSPF, page RC-241
• Path Computation Element for OSPFv2, page RC-241
OSPF Functional Overview
OSPF is a routing protocol for IP. It is a link-state protocol, as opposed to a distance-vector protocol. A
link-state protocol makes its routing decisions based on the states of the links that connect source and
destination machines. The state of the link is a description of that interface and its relationship to its
neighboring networking devices. The interface information includes the IP address of the interface,
network mask, type of network to which it is connected, routers connected to that network, and so on.
This information is propagated in various types of link-state advertisements (LSAs).