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Hands-on Lab·LPIC-1

Addresses, routes and what the mask decides

Topic 109 is weight 14, the largest on the 102 paper. This guide covers the half of it that is not DNS: what an interface is actually configured with, how the prefix length decides whether a packet goes direct or via the router, what is listening on the machine, and where each family keeps the configuration that survives a reboot - which is genuinely different on the two hosts.

102: Networking Fundamentals Guide 21 of 33 Beginner

Two hosts on one subnet - .76 Debian-family, .77 RPM-family - so every claim about reaching another machine is tested against a machine that is really there.
Server NameIP AddressOSRolesCPURAMHDD
LPIC1-A01192.168.0.76Ubuntu 26.04 LTSDebian-family host - dpkg and apt, which objective 102.4 names2 Core4 GB50 GB
LPIC1-B01192.168.0.77AlmaLinux 10.2RPM-family host - rpm and dnf, which objective 102.5 names2 Core4 GB50 GB

This guide includes

Use this for the largest topic on the 102 paper. This matters because the mask decides who counts as a neighbour - and that is the whole difference between the two routes on this machine.

Before you start

  1. What the interface is actually configured with

  2. The mask decides who is a neighbour

  3. What is listening, and what is connected

  4. Where the configuration lives after a reboot

Official sources

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