The Router's View

Lesson 45 of 46 in Coddy's IP Addressing and Subnetting course.

A subnet is only useful if its machines can leave it, and they leave through the gateway: the router interface that lives inside the subnet.

By near-universal convention the gateway takes the first usable host address of each subnet: network address plus one. Machines are then configured with it as their default route.

So finishing the plan means walking your allocation list once more and adding one to each network address. That list is what actually gets typed into the router.

Challenge

Easy

Print the gateway address for each of the four subnets you allocated, one per line, same order as before (Engineering, Sales, Support, Printers).

Expected output:

10.20.0.1
10.20.0.129
10.20.0.193
10.20.0.225

Try it yourself

Terminal

All lessons in IP Addressing and Subnetting

1Bits and Binary

Numbers as Bits Binary to Decimal Powers of Two Recap - Binary Warm-up

4CIDR Notation

Goodbye Classes Reading CIDR Block Sizes Recap - CIDR Reading

7Special Addresses

Private Ranges Loopback Link-Local Zero and Broadcast

10Capstone - The Office

The Floor Plan Sizing Each Team Carving the BlockThe Router's ViewRecap - Ship the Plan

2IPv4 Anatomy

Four Octets The 32-Bit View Network and Host Valid or Not Recap - Read an Address

5Inside a Subnet

Network Address Broadcast Address Usable Hosts First and Last Host Recap - Subnet Facts

8Planning Networks

Right-Sizing VLSM Step by Step Allocation Order Checking for Overlap Recap - Plan a Network

3The Subnet Mask

What a Mask Does Mask to Prefix Prefix to Mask ANDing It Out Recap - Mask Basics

6Subnetting Drills

The Block Size Trick Which Subnet Am I In Splitting a /24 Splitting Again Recap - Subnetting Drills

9IPv6 First Steps

Why IPv6 Reading IPv6 Prefixes in IPv6 Recap - IPv6 Basics

Practice on your own: Terminal playground