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..
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 Multilink Frame Relay on Cisco Routers
This section looks at the configuration tasks required to configure the Multilink Frame Relay feature on a Cisco router. In addition, all Multilink Frame Relay-related commands supported by the Cisco IOS are discussed. The following procedures outline the steps required to create a bundle interface, configure the physical serial interfaces as bundle links, and associate the bundle links with the bundle interface. The optional configuration commands for tuning Multilink Frame..
OSPF authentication causes routers to authenticate every OSPF message. To do so, the routers use the same preshared key value, generating an MD5 digest for each OSPF message and sending that digest as part of each OSPF message. If a router configured for OSPF authentication receives an OSPF message, and the received message’s MD5 digest does not pass the authentication checking based on the local key value, the router silently discards the message. As a result, when a..
