Implementing IS-IS on Cisco IOS XR Software

How to Implement IS-IS on Cisco IOS XR Software

DETAILED STEPS

 

Command or Action

Purpose

Step 1

 

 

configure

Enters global configuration mode.

 

Example:

 

 

RP/0/RP0/CPU0:router# configure

 

Step 2

 

 

router isis instance-id

Enables IS-IS routing for the specified routing instance, and

 

 

places the router in router configuration mode.

 

Example:

• You can change the level of routing to be performed by

 

RP/0/RP0/CPU0:router(config)# router isis isp

a particular routing instance using the is-typerouter

 

 

configuration command.

Step 3

 

 

lsp-refresh-interval seconds [level {1 2}]

(Optional) Sets the time between regeneration of LSPs that

 

 

contain different sequence numbers

 

Example:

• The refresh interval should always be set lower than the

 

RP/0/RP0/CPU0:router(config-isis)#

max-lsp-lifetime command.

 

lsp-refresh-interval 10800

 

Step 4

 

 

lsp-check-interval seconds [level {1 2}]

(Optional) Configures the time between periodic checks of

 

 

the entire database to validate the checksums of the LSPs in

 

Example:

the database.

 

 

 

RP/0/RP0/CPU0:router(config-isis)#

• This operation is costly in terms of CPU and so should

 

lsp-check-interval 240

be configured to occur infrequently.

 

 

 

Step 5

lsp-gen-interval {[initial-wait initial

(Optional) Reduces the rate of LSP generation during

 

secondary-wait secondary maximum-wait

periods of instability in the network. Helps reduce the CPU

 

maximum] ...}[level {1 2}]

 

load on the router and number of LSP transmissions to its

 

 

 

 

IS-IS neighbors.

 

Example:

• During prolonged periods of network instability,

 

RP/0/RP0/CPU0:router(config-isis)#

 

repeated recalculation of LSPs can cause an increased

 

lsp-gen-interval maximum-wait 15 initial-wait 5

 

CPU load on the local router. Further, the flooding of

 

 

 

 

these recalculated LSPs to the other Intermediate

 

 

Systems in the network causes increased traffic and can

 

 

result in other routers having to spend more time

 

 

running route calculations.

Step 6

 

 

lsp-mtu bytes [level {1 2}]

(Optional) Sets the maximum transmission unit (MTU) size

 

 

of LSPs.

 

Example:

 

 

RP/0/RP0/CPU0:router(config-isis)# lsp-mtu 1300

 

Step 7

 

 

max-lsp-lifetime seconds [level {1 2}]

(Optional) Sets the initial lifetime given to an LSP

 

 

originated by the router.

 

Example:

• This is the amount of time that the LSP persists in the

 

RP/0/RP0/CPU0:router(config-isis)#

database of a neighbor unless the LSP is regenerated or

 

max-lsp-lifetime 11000

refreshed.

 

 

 

Cisco IOS XR Routing Configuration Guide

RC-103

Page 118 Page 120
Page 119
Image 119
Cisco Systems IOS XR manual Max-lsp-lifetime command, RC-103
Page 118 Page 120

IOS XR specifications

Cisco Systems IOS XR is an advanced operating system designed specifically for high-performance routers and service provider networks. It serves as the backbone for many of Cisco's high-end routing platforms, enabling service providers to manage their networks with increased efficiency, flexibility, and scalability.

One of the main features of IOS XR is its modular architecture. This allows for the independent operation of various components within the OS, facilitating the deployment of new features and updates without affecting the overall stability of the system. This modularity ensures that service providers can implement rapid changes and enhancements while maintaining service continuity.

Another characteristic of IOS XR is its support for 64-bit architecture, which provides enhanced performance and the ability to manage larger amounts of data. This is particularly beneficial for service providers that deal with high traffic volumes and require robust data processing capabilities. The utilization of 64-bit technology also enables the operating system to utilize memory more efficiently, allowing for greater scalability.

IOS XR incorporates advanced technologies such as Distributed System Architecture (DSA) and Multiple Routing Instances (Merging Routes). DSA allows for the distribution of routing processes across multiple hardware resources, maximizing performance and redundancy. Multiple Routing Instances enable operators to create separate logical routing tables for different services, improving isolation and efficiency in managing network traffic.

The operating system also focuses heavily on security, featuring extensive encryption methods and access controls to safeguard network resources. IOS XR supports various authentication protocols, ensuring secure access to routers and switches. In addition, the OS includes comprehensive logging and monitoring capabilities, allowing network administrators to track activities and respond quickly to potential threats.

Another critical aspect of IOS XR is its adherence to the principles of service-oriented architecture (SOA). This approach permits the development of applications and services that can operate independently, fostering innovation and enabling service providers to tailor their offerings based on customer demands.

Ultimately, Cisco IOS XR is a powerful, reliable operating system that meets the complex needs of modern telecommunications networks. With its focus on modularity, performance, security, and scalability, it enables service providers to deliver high-quality, resilient services to their customers while efficiently managing network resources. As the industry continues to evolve, IOS XR remains a vital tool for those aiming to stay competitive in the ever-changing landscape of networking.
Top Page Image Contents