Cisco ASR 9000 Series Aggregation Services Router IP Addresses and Services Configuration Guide, Release 4.1
Configuring Transports
Downloads: This chapterpdf (PDF - 1.14MB) The complete bookPDF (PDF - 4.41MB) | Feedback

Configuring Transports

Configuring Transports

This module provides information about Nonstop Routing (NSR), Transmission Control Protocol (TCP), and User Datagram Protocol (UDP) transports on Cisco ASR 9000 Series Aggregation Services Routers .

If you have specific requirements and need to adjust the NSR, TCP, or UDP values, refer to the Transport Stack Commands on Cisco ASR 9000 Series Aggregation Services Router IP Addresses and Services Command Reference.


Note


For a complete description of the transport configuration commands listed in this module, refer to the Cisco ASR 9000 Series Aggregation Services Router IP Addresses and Services Command Reference publication. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.


Feature History for Configuring NSR, SCTP, TCP, UDP, and UDP RAW Transports on the Cisco ASR 9000 Series Router

Release

Modification

Release 3.7.2

This feature was introduced.

Prerequisites for Configuring NSR, TCP, UDP Transports

The following prerequisites are required to implement NSR, TCP, UDP Transports:

You must be in a user group associated with a task group that includes the proper task IDs. The command reference guides include the task IDs required for each command. If you suspect user group assignment is preventing you from using a command, contact your AAA administrator for assistance.

Information About Configuring NSR, TCP, UDP Transports

To configure NSR, TCP, and UDP transports, you must understand the following concepts:

NSR Overview

Nonstop Routing (NSR) is provided for Open Shortest Path First (OSPF) and Label Distribution Protocol (LDP) protocols for the following events:

  • Route Processor (RP) failover
  • Process restart for either OSPF, LDP, or TCP
  • In-service software upgrades (ISSU)

In the case of the RP failover, NSR is achieved by for both TCP and the applications (OSPF or LDP).

NSR is a method to achieve High Availability (HA) of the routing protocols. TCP connections and the routing protocol sessions are migrated from the active RP to standby RP after the RP failover without letting the peers know about the failover. Currently, the sessions terminate and the protocols running on the standby RP reestablish the sessions after the standby RP goes active. Graceful Restart (GR) extensions are used in place of NSR to prevent traffic loss during an RP failover but GR has several drawbacks.

You can use the nsr process-failures switchover command to let the RP failover be used as a recovery action when the active TCP or active LDP restarts. When standby TCP or LDP restarts, only the NSR capability is lost till the standby instances come up and the sessions are resynchronized but the sessions do not go down. In the case of the process failure of an active OSPF, a fault-management policy is used. For more information, refer to Implementing OSPF on Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide.

TCP Overview

TCP is a connection-oriented protocol that specifies the format of data and acknowledgments that two computer systems exchange to transfer data. TCP also specifies the procedures the computers use to ensure that the data arrives correctly. TCP allows multiple applications on a system to communicate concurrently, because it handles all demultiplexing of the incoming traffic among the application programs.

Any IP protocol other than TCP or UDP is known as a RAW protocol.

For most sites, the default settings for the TCP, UDP, and RAW transports need not be changed.

UDP Overview

The User Datagram Protocol (UDP) is a connectionless transport-layer protocol that belongs to the IP family. UDP is the transport protocol for several well-known application-layer protocols, including Network File System (NFS), Simple Network Management Protocol (SNMP), Domain Name System (DNS), and TFTP.

Any IP protocol other than TCP, UDP, is known as a RAW protocol.

For most sites, the default settings for the TCP, UDP, and RAW transports need not be changed.

How to Configure Failover as a Recovery Action for NSR

This section contains the following procedure:

Configuring Failover as a Recovery Action for NSR

This task allows you to configure failover as a recovery action to process failures of active instances.

When the active TCP or the NSR client of the active TCP terminates or restarts, the TCP sessions go down. To continue to provide NSR, failover is configured as a recovery action. If failover is configured, a switchover is initiated if the active TCP or an active application (for example, LDP, OSPF, and so forth) restarts or terminates.

For information on how to configure MPLS Label Distribution Protocol (LDP) for NSR, refer to the Cisco ASR 9000 Series Aggregation Services Router MPLS Configuration Guide.

For information on how to configure NSR on a per-process level for each OSPF process, refer to the Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide.

SUMMARY STEPS

    1.    configure

    2.    nsr process-failures switchover

    3.    Use one of these commands:

    • end
    • commit


DETAILED STEPS
      Command or Action Purpose
    Step 1 configure


    Example:
    RP/0/RSP0/CPU0:router# configure
     

    Enters global configuration mode.

     
    Step 2 nsr process-failures switchover


    Example:
    
    RP/0/RSP0/CPU0:router(config)# nsr process-failures switchover
    
    
    
     

    Configures failover as a recovery action for active instances to switch over to a standby route processor (RP) or a distributed route processor (DRP) to maintain nonstop routing (NSR.

     
    Step 3 Use one of these commands:
    • end
    • commit


    Example:
    RP/0/RSP0/CPU0:router(config)# end

    or

    RP/0/RSP0/CPU0:router(config)# commit
     

    Saves configuration changes.

    • When you issue the end command, the system prompts you to commit changes:
      Uncommitted changes found, commit them
      before exiting(yes/no/cancel)? [cancel]:
      
      • Entering yes saves configuration changes to the running configuration file, exits the configuration session, and returns the router to EXEC mode.
      • Entering no exits the configuration session and returns the router to EXEC mode without committing the configuration changes.
      • Entering cancel leaves the router in the current configuration session without exiting or committing the configuration changes.
    • Use the commit command to save the configuration changes to the running configuration file, and remain within the configuration session.
     

    Additional References

    The following sections provide references related to configuring NSR, TCP, and UDP transports.

    Related Documents

    Related Topic

    Document Title

    the Cisco ASR 9000 Series Router Transport Stack commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples

    Transport Stack Commands in the Cisco ASR 9000 Series Aggregation Services Router IP Addresses and Services Command Reference

    the Cisco ASR 9000 Series Router MPLS LDP commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples

    MPLS Label Distribution Protocol Commands in the Cisco ASR 9000 Series Aggregation Services Router MPLS Command Reference

    the Cisco ASR 9000 Series Router OSPF commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples

    OSPF Commands in the Cisco ASR 9000 Series Aggregation Services Router Routing Command Reference

    MPLS Label Distribution Protocol feature information

    Implementing MPLS Label Distribution Protocol in the Cisco ASR 9000 Series Aggregation Services Router MPLS Configuration Guide

    OSPF feature information

    Implementing OSPF in the Cisco ASR 9000 Series Aggregation Services Router Routing Configuration Guide

    Standards

    Standards

    Title

    No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.

    MIBs

    MIBs

    MIBs Link

    To locate and download MIBs, use the Cisco MIB Locator found at the following URL and choose a platform under the Cisco Access Products menu: http:/​/​cisco.com/​public/​sw-center/​netmgmt/​cmtk/​mibs.shtml

    RFCs

    RFCs

    Title

    No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.

    Technical Assistance

    Description

    Link

    The Cisco Technical Support website contains thousands of pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.

    http:/​/​www.cisco.com/​techsupport