Configuring
Transports
This module provides
information about Nonstop Routing (NSR),
Transmission Control Protocol (TCP),
User Datagram Protocol (UDP
), and RAW Transports.
If you have specific
requirements and need to adjust the NSR,
TCP, UDP, or
RAW
values, refer to the
Transport Stack
Commands on
IP Addresses and Services
Command Reference for Cisco NCS 6000 Series Routers.
Feature History
for Configuring NSR,
TCP, UDP, and UDP RAW Transports
Release
|
Modification
|
Release 5.0.0
|
This
feature was introduced.
|
Prerequisites for
Configuring NSR,
TCP, UDP,
and RAW
Transports
The following
prerequisites are required to implement NSR,
TCP, UDP,
and RAW 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, and RAW
Transports
To configure NSR,
TCP, UDP, and
RAW
transports, you must understand the following concepts:
NSR Overview
Nonstop Routing (NSR)
is provided for Open Shortest Path First (OSPF), Border Gateway Protocol
(BGP), and Label Distribution Protocol (LDP) protocols for the following
events:
-
Route Processor
(RP)
failover
-
Process restart
for either OSPF, LDP, or TCP
-
Online insertion
removal (OIR)
In the case of the RP
failover, NSR is achieved by for both TCP and the applications (OSPF, BGP, 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
Routing Configuration Guide for Cisco NCS 6000 Series
Routers.
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.
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
MPLS Configuration Guide for
Cisco NCS 6000 Series Routers.
For information on
how to configure NSR on a per-process level for each
process, refer to the
Routing Configuration Guide for Cisco NCS 6000 Series
Routers.
 Note |
Before performing
this procedure, enable RP isolation using the
isolation
enable command for improved troubleshooting. Without enabling RP
isolation, the failing process will not generate the logs required to find the
root cause of the failure.
|
SUMMARY STEPS1.
configure
2.
nsr
process-failures switchover
3.
commit
DETAILED STEPS | Command or Action | Purpose |
---|
Step 1 |
configure
|
|
Step 2 |
nsr
process-failures switchover
Example:
RP/0/RP0/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) to maintain nonstop routing (NSR.
|
Step 3 |
commit
|
|
Additional References
The following sections provide references related to configuring NSR, TCP, and
transports.
Related Documents
Related Topic
|
Document Title
|
Transport Stack commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples
|
Transport Stack Commands in the
IP Addresses and Services
Command Reference for Cisco NCS 6000 Series Routers
|
MPLS LDP commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples
|
MPLS Label Distribution Protocol Commands in the
MPLS Command Reference for Cisco NCS 6000 Series Routers
|
OSPF commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples
|
OSPF Commands in the
Routing Command Reference for
Cisco NCS 6000 Series Routers
|
MPLS Label Distribution Protocol feature information
|
Implementing MPLS Label Distribution Protocol in the
MPLS Configuration Guide for
Cisco NCS 6000 Series Routers
|
OSPF feature information
|
Implementing OSPF in the
Routing Configuration Guide for Cisco NCS 6000 Series
Routers
|
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.
|
— |
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.
|
— |
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|
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|
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