What's changed: Initial version
4.3Basic routing concepts
Covers the default gateway as the exit when leaving your own network (to another network), the difference between an L2 switch (forwarding within one segment by MAC) and an L3 switch (which can also route between networks), and how forwarding changes by whether the destination is on the local network or a remote network—as the foundation for telling "does this destination go via the gateway or arrive directly."
Many faults of the form "I reach people in the same room but only the outside server is unreachable" are about the exit to another network. Every time, a PC decides: if the destination is on its own network (the local network), hand it directly to the peer; if on a different network (a remote network), hand it to the default gateway, the "exit to the outside." This section covers the role of that exit and the difference between an L2 switch (handling within one segment) and an L3 switch (which can also route between networks), as the introductory basis for telling "does this destination go directly or via the gateway."
4.3.1Default gateway and local/remote
Continue reading — free sign-up
You're reading the free preview. Sign up free to read this section in full, plus every chapter (including 4+) and all questions.