Laptop User Manual
Table Of Contents
- Cisco IOS XR Routing Configuration Guide
- Contents
- Preface
- Document Revision History
- Obtaining Documentation
- Documentation Feedback
- Cisco Product Security Overview
- Obtaining Technical Assistance
- Obtaining Additional Publications and Information
- Implementing BGP on Cisco IOS XR Software
- Contents
- Prerequisites for Implementing BGP on CiscoIOSXR Software
- Information About Implementing BGP on CiscoIOSXR Software
- BGP Functional Overview
- BGP Router Identifier
- BGP Default Limits
- BGP Validation of Local Next-Hop Addresses
- BGP Configuration
- No Default Address Family
- Routing Policy Enforcement
- Table Policy
- Update Groups
- BGP Best Path Algorithm
- Multiprotocol BGP
- Route Dampening
- BGP Routing Domain Confederation
- BGP Route Reflectors
- Default Address Family for show Commands
- How to Implement BGP on CiscoIOSXR Software
- Enabling BGP Routing
- Configuring a Routing Domain Confederation for BGP
- Resetting eBGP Session Immediately Upon Link Failure
- Logging Neighbor Changes
- Adjusting BGP Timers
- Changing the BGP Default Local Preference Value
- Configuring the MED Metric for BGP
- Configuring BGP Weights
- Tuning the BGP Best Path Calculation
- Indicating BGP Backdoor Routes
- Configuring Aggregate Addresses
- Redistributing iBGP Routes into IGP
- Redistributing Prefixes into Multiprotocol BGP
- Configuring BGP Route Dampening
- Applying Policy When Updating the Routing Table
- Setting BGP Administrative Distance
- Configuring a BGP Neighbor Group
- Configuring a BGP Neighbor
- Configuring a Route Reflector for BGP
- Configuring BGP Route Filtering by Route Policy
- Disabling Next Hop Processing on BGP Updates
- Configuring BGP Community and Extended-Community Filtering
- Configuring Software to Store Updates from a Neighbor
- Disabling a BGP Neighbor
- Resetting Neighbors Using BGP Dynamic Inbound Soft Reset
- Resetting Neighbors Using BGP Outbound Soft Reset
- Resetting Neighbors Using BGP Hard Reset
- Clearing Caches, Tables and Databases
- Displaying System and Network Statistics
- Monitoring BGP Update Groups
- Configuration Examples for Implementing BGP on CiscoIOSXR Software
- Where to Go Next
- Additional References
- Implementing IS-IS on Cisco IOS XR Software
- Contents
- Prerequisites for Implementing IS-IS on CiscoIOSXR Software
- Restrictions for Implementing IS-IS on CiscoIOSXR Software
- Information About Implementing IS-IS on CiscoIOSXR Software
- IS-IS Functional Overview
- Key Features Supported in the CiscoIOSXR IS-IS Implementation
- IS-IS Configuration Grouping
- IS-IS Interfaces
- Multitopology Configuration
- IPv6 Routing and Configuring IPv6 Addressing
- Limit LSP Flooding
- Maximum LSP Lifetime and Refresh Interval
- Overload Bit Configuration During Multitopology Operation
- Single-Topology IPv6 Support
- Multitopology IPv6 Support
- Nonstop Forwarding
- Multi-Instance IS-IS
- Multiprotocol Label Switching Traffic Engineering
- Overload Bit on Router
- Default Routes
- Attached Bit on an IS-IS Instance
- Multicast-Intact Feature
- How to Implement IS-IS on CiscoIOSXR Software
- Enabling IS-IS and Configuring Level 1 or Level 2 Routing
- Configuring Single Topology for IS-IS
- Configuring Multitopology for IS-IS
- Controlling LSP Flooding for IS-IS
- Configuring Nonstop Forwarding for IS-IS
- Configuring Authentication for IS-IS
- Configuring MPLS Traffic Engineering for IS-IS
- Tuning Adjacencies for IS-IS on Point-to-Point Interfaces
- Setting SPF Interval for a Single-Topology IPv4 and IPv6 Configuration
- Enabling Multicast-Intact for IS-IS
- Customizing Routes for IS-IS
- Configuration Examples for Implementing IS-IS on CiscoIOSXR Software
- Where to Go Next
- Additional References
- Implementing OSPF on Cisco IOS XR Software
- Contents
- Prerequisites for Implementing OSPF on CiscoIOSXR Software
- Information About Implementing OSPF on CiscoIOSXR Software
- OSPF Functional Overview
- Key Features Supported in the CiscoIOSXR OSPF Implementation
- Comparison of CiscoIOSXR OSPFv3 and OSPFv2
- Importing Addresses into OSPFv3
- OSPF Hierarchical CLI and CLI Inheritance
- OSPF Routing Components
- OSPF Process and Router ID
- Supported OSPF Network Types
- Route Authentication Methods for OSPF Version 2
- Neighbors and Adjacency for OSPF
- Designated Router (DR) for OSPF
- Default Route for OSPF
- Link-State Advertisement Types for OSPF Version 2
- Link-State Advertisement Types for OSPFv3
- Virtual Link and Transit Area for OSPF
- Route Redistribution for OSPF
- OSPF Shortest Path First Throttling
- Nonstop Forwarding for OSPF Version 2
- Load Balancing in OSPF Version 2 and OSPFv3
- Graceful Restart for OSPFv3
- Multicast-Intact Feature
- How to Implement OSPF on CiscoIOSXR Software
- Enabling OSPF
- Configuring Stub and Not-so-Stubby Area Types
- Configuring Neighbors for Nonbroadcast Networks
- Configuring Authentication at Different Hierarchical Levels for OSPF Version 2
- Controlling the Frequency that the Same LSA Is Originated or Accepted for OSPF
- Creating a Virtual Link with MD5 Authentication to Area 0 for OSPF
- Summarizing Subnetwork LSAs on an OSPF ABR
- Redistributing Routes from One IGP into OSPF
- Configuring OSPF Shortest Path First Throttling
- Configuring Nonstop Forwarding for OSPF Version 2
- Configuring OSPF Version 2 for MPLS Traffic Engineering
- Verifying OSPF Configuration and Operation
- Configuring OSPFv3 Graceful Restart
- Enabling Multicast-Intact for OSPFv2
- Configuration Examples for Implementing OSPF on CiscoIOSXR Software
- CiscoIOSXR for OSPF Version 2 Configuration: Example
- CLI Inheritance and Precedence for OSPF Version 2: Example
- MPLS TE for OSPF Version 2: Example
- ABR with Summarization for OSPFv3: Example
- ABR Stub Area for OSPFv3: Example
- ABR Totally Stub Area for OSPFv3: Example
- Route Redistribution for OSPFv3: Example
- Virtual Link Configured Through Area 1 for OSPFv3: Example
- Virtual Link Configured with MD5 Authentication for OSPF Version 2: Example
- Where to Go Next
- Additional References
- Implementing and Monitoring RIB on CiscoIOSXR Software
- Contents
- Prerequisites for Implementing RIB on CiscoIOSXR Software
- Information About RIB Configuration
- How to Deploy and Monitor RIB
- Configuration Examples for RIB Monitoring
- Output of show route Command: Example
- Output of show route backup Command: Example
- Output of show route best-local Command: Example
- Output of show route connected Command: Example
- Output of show route local Command: Example
- Output of show route longer-prefixes Command: Example
- Output of show route next-hop Command: Example
- Where to Go Next
- Additional References
- Implementing Routing Policy on Cisco IOS XR Software
- Implementing Static Routes on Cisco IOS XR Software
- Index
Implementing OSPF on Cisco IOS XR Software
Information About Implementing OSPF on Cisco IOS XR Software
RC-143
Cisco IOS XR Routing Configuration Guide
• Upon entering helper mode, a router performs its helper function for a specific period of time. This
time period is the lifetime value from the router that is in restart mode—minus the value of lsage in
the received grace LSA. If the graceful restart succeeds in time, the helper’s timer is stopped before
it expires. If the helper’s timer does expire, the adjacency to the restarting router is brought down,
and normal OSPFv3 functionality resumes.
• The dead timer is not honored by the router that is in helper mode.
• A router in helper mode ceases to perform the helper function in any of the following cases:
–
The helper router is able to bring up a FULL adjacency with the restarting router.
–
The local timer for the helper function expires.
Graceful Restart Requirements and Restrictions
The requirements for supporting the Graceful Restart feature include:
• Cooperation of a router’s neighbors during a graceful restart. In relation to the router on which
OSPFv3 is restarting, each router is called a helper.
• All neighbors of the router that does a graceful restart must be capable of doing a graceful restart.
• A graceful restart does not occur upon the first-time startup of a router.
• OSPFv3 neighbor information and database information are not check-pointed.
• An OSPFv3 process rebuilds adjacencies after it restarts.
• To ensure consistent databases after a restart, the OSPFv3 configuration must be identical to the
configuration before the restart. (This requirement applies to self-originated information in the local
database.) A graceful restart can fail if configurations change during the operation. In this case, data
forwarding would be affected. OSPFv3 resumes operation by regenerating all its LSAs and
resynchronizing its database with all its neighbors.
• Although IPv6 FIB tables remain unchanged during a graceful restart, these tables eventually mark
the routes as stale through the use of a holddown timer. Enough time is allowed for the protocols to
rebuild state information and converge.
• The router on which OSPFv3 is restarting must send OSPFv3 hellos within the dead interval of the
process restart. Protocols must be able to retain adjacencies with neighbors before the adjacency
dead timer expires. The default for the dead timer is 40 seconds. If hellos do not arrive on the
adjacency before the dead timer expires, the router takes down the adjacency. The OSPFv3 Graceful
Restart feature does not function properly if the dead timer is configured to be less than the time
required to send hellos after the OSPFv3 process restarts.
• Simultaneous graceful restart sessions on multiple routers are not supported on a single network
segment. If a router determines that multiple routers are in restart mode, it terminates any local
graceful restart operation.
• This feature utilizes the available support for changing the purge time of existing OSPFv3 routes in
the routing information base (RIB). When graceful restart is enabled, the purge timer is set to 90
seconds by default. If graceful restart is disabled, the purge timer setting is 0.
• This feature has an associated grace LSA. This link-scope LSA is type 11.
• According to the RFC, the OSPFv3 process should flush all old, self-originated LSAs during a
restart. With the Graceful Restart feature, however, the router delays this flushing of unknown
self-originated LSAs during a graceful restart. OSPFv3 can learn new information and build new
LSAs to replace the old LSAs. When the delay is over, all old LSAs are flushed.