The Missing Gateway

Lesson 20 of 35 in Coddy's LAN Labs course.

"I can ping the server from my desk, but the server cannot ping me" is one of the most reported LAN problems, and it is almost never the server. It is the reply path: the far side has no default gateway, so it can receive the request and has nowhere to send the answer.

netlab's no reply wording tells you which side is stuck and what it believes. Fix the gateway on the machine named in the message, not the one you are typing on.

Challenge

Easy

Ping pc3 from pc1, read which host lacks a gateway, set it to the router's address in that network, and ping again.

Expected output:

pc1 -> pc3: no reply (pc3 thinks 192.168.1.10 is on a different subnet and has no gateway)
pc3: gateway 10.0.0.1
pc1 -> pc3: reply from 10.0.0.20 (ttl=63, via r1)

Try it yourself

Terminal