The router uses an IP routing table, or routing information base (RIB) to forward packets. The RIB is a table of • Destination network • Port to forward traffic through • Next hop information Figure 3-9 illustrates a network and corresponding routing tables. Figure 3-9 A Network and Routing Tables From router C’s perspective, there…
Author: Isabella Hayes
Note This section describes what the Spanning Tree Protocol accomplishes and why it is important. The operation of SPT is outside the scope of this book. A single switch might be useful in some situations, but to build a large network, you are going to need more than one. How do hosts communicate when there…
If A, B, D, and E are running IPv6, the Neighbor Discovery (ND) protocol is used to map physical interface addresses. One major difference between IPv4 and IPv6 is that IPv6 hosts do not assume every other host on the segment is using the same prefix. Figure 3-5 illustrates. Figure 3-5 IPv6 Neighbor Discovery Because…
on a Single Wire – Ciscco Certifed Support Technici Once all the hosts connected to a single segment have physical and interface addresses, they can begin to communicate. Figure 3-4 will be used to explain the process. Figure 3-4 Host-to-Host Communication In the figure, each of these hosts has two addresses: a physical address and…
Users tend to think of “the network” as a sort of virtual thing: it exists “out there,” but where “there” is, and how bits are translated into signals, signals are carried from place to place, and data is processed are all something of a mystery. Network engineers, however, know that while networks can be described…
All equipment used in information technology—hosts, routers, switches, and even copper cables—generates heat during operation. However, operating equipment at higher temperatures can reduce its life span or—if the temperature is high enough—cause immediate failures. Heat is managed in information technology operations by • Vendors working to reduce the heat their devices produce. • Vendors designing…
Every network engineer—at some point in their career, at least—runs network wiring, so it is essential to understand how to perform this fundamental task. Figure 10-9 illustrates cable management. Figure 10-9 With and Without Cable Management The left side of Figure 10-9 shows a rack cabled without management aids, bundling, or even separation. The result…
Networking diagrams are crucial to the documentation required to operate, troubleshoot, and modify a network. Building a good network diagram requires a solid grasp of how the network is built, how it works, and what the diagram itself is supposed to accomplish. There are two broad categories of network diagrams: physical and logical. Figure 10-7…
Once network parameters are configured, you must verify the configuration is correct. ping and traceroute are the two most widely used utilities. The network in Figure 4-16 will be used throughout this section to illustrate tools commonly used to verify connectivity and their use. Figure 4-16 Verifying Connectivity Ping The first application to use when…
Traceroute is another helpful piece of network diagnostics software installed on most hosts. Traceroute takes advantage of the TTL in each IP packet to find the path between the local host and a destination. If you run a traceroute from host A in Figure 4-16 toward E: 1. The traceroute application at A will send…