Loss of Information Inside Aggregates

Aggregation causes loss of granularity. The detailed information that exists in the specific prefixes will be lost when summarized in the form of aggregates. The purpose of an AS_SET is to attempt to preserve the attributes carried in the specific routes in a mathematical SET that gives a better idea of the elements of the aggregate. Figure 11-13 illustrates the network topology for this scenario. Figure 11-13. Dealing with Loss of Information with Aggregates   In Figu..

Overlapping Virtual Private Networks

The SuperCom example might lead you to believe that a VPN is associated with a single VRF in a PE-router. Although that would be true in the case where the VPN customer needs no connectivity with other VPN customers, the situation might become more complex and require more than one VRF per VPN customer. Imagine that SuperCom wants to extend its service offering with a Voice over IP (VoIP) service with gateways to the public voice network located in San Jose and Paris, as sho..

Auto-Summary: Enhanced IGRP Summarization and Query

Scoping   Query propagationoccurs when an Enhanced IGRP router loses a route to a destination, and therefore goes into an active state. During this process, the router queries all its neighbors for the lost destination. Query propagation stops one hop from the point of summarization and auto- summary.   This is a definite advantage—if all the routes were sent across to all the routers in the network, a remote node in one part of the network would sen..

Vulnerabilities, Attacks, and Common Exploits

This section covers some of the vulnerabilities in TCP/IP and the tools used to exploit IP networks. TCP/IP is an open standard protocol, which means that both network administrators and intruders are aware of the TCP/IP architecture and vulnerabilities. Note There are a number of network vulnerabilities, such as insufficient password protection, lack of authentication mechanisms, use of unprotected routing protocols, and firewall holes. This section concentrates on TCP/IP..

Configuring Frame Relay Traffic Shaping

This section discusses the IOS configuration commands for configuring Frame Relay Traffic Shaping on a Cisco router. NOTE For this discussion, IOS Release 12.2(1) was used on all routers in the lab to maintain a consistency of software versions. The same release was used in the case study scenarios at the end of this chapter. Before configuring Frame Relay Traffic Shaping on a Cisco router, you must enable Frame Relay encapsulation on the main interface. By default, config..