Skip to content
Skip to main content

About this free course

Download this course

Share this free course

Discovering computer networks: hands on in the Open Networking Lab
Discovering computer networks: hands on in the Open Networking Lab

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

14.1 Troubleshooting the routing process

In this section you are going to troubleshoot the demonstration network shown in Figure 1. You’ll look at the routing tables of the routers to see why ping packets cannot reach their destinations.

Figure _unit8.2.1 Figure 1

Watch the video, which is about 2 minutes long.

Box _unit8.2.1 Troubleshooting the routing process

Download this video clip.Video player: 75_troubleshooting_the_routing_process.mp4
Copy this transcript to the clipboard
Print this transcript
Show transcript|Hide transcript
Interactive feature not available in single page view (see it in standard view).

Activity _unit8.2.1 Activity 1 Think about

10 minutes

1. In the video, when we pinged PC2 from PC1, the first ping timed out, whereas the remaining three succeeded. Write one or two sentences to explain what you think the reason is for this.


This happened because the ARP table in PC1 did not have an entry from PC2, so an ARP request was issued to find it. This process takes some time, which caused the first ping packet to time out.


An interface has had its IP address wrongly configured.


One of the routers has an interface down.


There is no route in Router 1’s routing table for the destination network.


The destination PC is switched off.

The correct answer is c.


Yes. In Router 1’s routing table, there is no known route from Router 1 to Router 2 for packets addressed to anything in the network.