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 BGP on Cisco IOS XR Software
Information About Implementing BGP on Cisco IOS XR Software
RC-16
Cisco IOS XR Routing Configuration Guide
Routing Policy Enforcement
External BGP (eBGP) neighbors must have an inbound and outbound policy configured. If no policy is
configured, no routes are accepted from the neighbor, nor are any routes advertised to it. This added
security measure ensures that routes cannot accidentally be accepted or advertised in the case of a
configuration omission error.
Note This enforcement affects only eBGP neighbors (neighbors in a different autonomous system than this
router). For internal BGP (iBGP) neighbors (neighbors in the same autonomous system), all routes are
accepted or advertised if there is no policy.
In the following example, for an eBGP neighbor, if all routes should be accepted and advertised with no
modifications, a simple pass-all policy is configured:
RP/0/RP0/CPU0:router(config)# route-policy pass-all
RP/0/RP0/CPU0:router(config-rpl)# pass
RP/0/RP0/CPU0:router(config-rpl)# end-policy
RP/0/RP0/CPU0:router(config)# commit
Use the route-policy (BGP) command in the neighbor address-family configuration mode to apply the
pass-all policy to a neighbor. The following example shows how to allow all IPv4 unicast routes to be
received from neighbor 192.168.40.42 and advertise all IPv4 unicast routes back to it:
RP/0/RP0/CPU0:router(config)# router bgp 1
RP/0/RP0/CPU0:router(config-bgp)# neighbor 192.168.40.24
RP/0/RP0/CPU0:router(config-bgp-nbr)# remote-as 2
RP/0/RP0/CPU0:router(config-bgp-nbr)# address-family ipv4 unicast
RP/0/RP0/CPU0:router(config-bgp-nbr-af)# route-policy pass-all in
RP/0/RP0/CPU0:router(config-bgp-nbr-af)# route-policy pass-all out
RP/0/RP0/CPU0:router(config-bgp-nbr-af)# commit
Use the show bgp summary command to display eBGP neighbors that do not have both an inbound and
outbound policy for every active address family. In the following example, such eBGP neighbors are
indicated in the output with an exclamation (!) mark:
RP/0/RP0/CPU0:router# show bgp all all summary
Address Family: IPv4 Unicast
============================
BGP router identifier 10.0.0.1, local AS number 1
BGP generic scan interval 60 secs
BGP main routing table version 41
BGP scan interval 60 secs
BGP is operating in STANDALONE mode.
Process RecvTblVer bRIB/RIB SendTblVer
Speaker 41 41 41
Neighbor Spk AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down St/PfxRcd
10.0.101.1 0 1 919 925 41 0 0 15:15:08 10
10.0.101.2 0 2 0 0 0 0 0 00:00:00 Idle
Address Family: IPv4 Multicast
==============================
BGP router identifier 10.0.0.1, local AS number 1
BGP generic scan interval 60 secs
BGP main routing table version 1