The drawback of confederations is that migration from a nonconfederation to a confederation design requires major reconfiguration of the routers and a major change in the logical topology. In addition, routing through a confederation might not take an optimal path without manually setting BGP policies. Figure 9-10 illustrates this issue. Figure 9-10. AS Confederation Internal and External Routing Confederation 100 is composed of three sub-ASs: 65010, 65020, and 65030...
CIDR is a convention defined in RFCs 1517 through 1520 that calls for aggregating routes for multiple classful network numbers into a single routing table entry. The primary goal of CIDR is to improve the scalability of Internet routers’ routing tables. Imagine the implications of an Internet router being burdened by carrying a route to every class A, B, and C network on the planet! CIDR uses both technical tools and administrative strategies to reduce the size of the Inter..
Types of Internetworking Devices
Cisco devices fall into three main categories: bridges and switches, routers, and access servers. We discuss bridges and switches first. Bridges and Switches A bridge is a network device that operates at the data link layer. A bridge connects multiple data link layer network segments into a single logical network segment. There are many different types of bridges: • Transparent or learning • Encapsulation • Translational • Source-route •&n..
The following configuration command adjusts the default packet size for all SNMP packets leaving the router: Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#snmp-server packetsize 1480 Router(config)#end Router# By default, Cisco routers limit their SNMP packet size to 1,500 bytes. It is usually not necessary to change this parameter. However, it may be useful to reduce it if your network has an MTU of less than 1,..
Sometimes funny things happen when the primary link comes back and the backup link has not yet disconnected. These problems are usually due to poor routing metrics, causing at least one of the routers to prefer the dial path, even if the primary is available. The easiest way to handle these problems is to use bandwidth commands to ensure that the primary is the better path: Router1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router1..
