Chapter 3 Configuring Open Shortest Path First

OSPF Overview

Autonomous System

The autonomous system (AS) is a collection of networks, under the same administrative control, that share the same routing information with each other. An AS is also referred to as a routing domain. Figure 3-1shows two ASs: AS A and AS B. An AS can consist of one or more OSPF areas.

Areas

Areas allow the subdivision of an AS into smaller, more manageable networks or sets of adjacent networks. As shown in Figure 3-1, AS A consists of three areas: area 0.0.0.0, area 1.1.1.1, and area 1.1.1.2.

OSPF hides the topology of an area from the rest of the AS. An area’s network topology is visible only to routers inside that area; the network topology is not visible to routers outside the area. When OSPF routing is within an area, this is called intra-area routing. This routing limits the amount of link-state information flooding onto the network, thereby reducing routing traffic. OSPF routing also reduces the size of the topology information in each router, which conserves processing and memory requirements in each router.

Conversely, the routers within an area cannot see detailed network structures outside the area. Because of this restriction of topological information, you can control traffic flow between areas and reduce routing traffic when the entire autonomous system is a single routing domain.

Backbone Area

A backbone area is responsible for distributing routing information between the areas of an autonomous system. When OSPF routing occurs outside of an area, this is called inter-area routing.

The backbone itself has all the properties of an area. It consists of ABRs, and routers and networks only on the backbone. As shown in Figure 3-1, area 0.0.0.0 is an OSPF backbone area. Note that a designated OSPF backbone area has a reserved ID of 0.0.0.0.

 

Cisco Content Services Switch Routing and Bridging Configuration Guide

3-4

OL-8241-02

Page 87 Page 89
Page 88
Image 88
Cisco Systems OL-8241-02 manual Autonomous System, Areas, Backbone Area
Page 87 Page 89

OL-8241-02 specifications

Cisco Systems OL-8241-02 is a significant component of Cisco's extensive portfolio, catering specifically to the needs of enterprise-level networking. This module is designed to provide advanced routing capabilities, aiding organizations in achieving robust connectivity and efficient data transmission across their networks. It is particularly popular among businesses that require reliable performance and scalability.

One of the main features of the OL-8241-02 module is its support for multiple protocols, including OSPF, EIGRP, and BGP, which allows for seamless integration into various network configurations. This flexibility ensures that organizations can adapt to evolving networking demands without undergoing complete infrastructure overhauls. Furthermore, the module includes advanced security features, such as IPsec VPN support and integrated firewall capabilities, enhancing overall network security and protecting sensitive data from potential threats.

Another noteworthy characteristic of the OL-8241-02 is its exceptional performance metrics. With high throughput rates and low latency, the module can handle significant amounts of data traffic without compromising on speed. This efficiency is particularly critical for businesses that rely heavily on real-time data applications, such as video conferencing and online collaboration tools.

The OL-8241-02 also incorporates cutting-edge technologies like Quality of Service (QoS), which prioritizes network traffic based on application requirements. This feature is essential for ensuring that critical applications receive the bandwidth they need, while less critical tasks can be deprioritized during peak usage times. Additionally, the module supports IPv6, which is vital for organizations looking to future-proof their network infrastructure amid the global transition from IPv4.

The ease of management is another highlight of the OL-8241-02, with user-friendly interfaces and compatibility with Cisco's robust management software. This capability allows IT teams to monitor performance metrics, troubleshoot issues, and configure settings with minimal complexity.

In summary, the Cisco Systems OL-8241-02 module stands out for its versatility, performance, and security features. Equipped with the ability to support various protocols, advanced security measures, and efficient traffic management, it proves to be a reliable choice for enterprises aiming to enhance their networking capabilities and ensure seamless operational continuity.
Top Page Image Contents