GNS3 – My Technical Test for Employers

I had an interesting requirement from a customer.

They asked me to implement a GNS3 server and design a 30 – 45 minute test that they could administrate to their candidates seeking a technical position with in their organisation.

The position was for a 2nd line network engineer role.

The test was to be aimed at CCNP level or equivalent, however I was to design it so that it is easy enough for even the rusty CCNP / engineers and hard enough for the complete brain dumpers and blaggers that serve to only dilute the IT industry with poor quality skill sets.

The main purpose of this test is to speed up the HR process by filtering the stronger candidates from the weaker candidates.

The successful candidates would then go ahead and progress to a final interview.

Here is the GNS3 test that I created for the purpose – To be honest, even a highly proficient CCNA engineer could do this 🙂

The .net files and pre-configuration files can be download from here


Configure the network as per the diagram and complete the tasks below.

  • Do NOT create any additional interfaces
  • Do NOT use any static routes or policy-based routes unless asked.
  • Ignore any duplex mismatch messages and do NOT modify any of the ports speed or duplex configurations.

Task 1: Configure an 802.1q trunk between SW1 fa1/15 interface and SW2 fa1/15 interface.

Task 2: Configure a static ether-channel 802.1Q trunk between SW1 and SW2. Both switches fa1/10 and fa1/11 interfaces should be members of the same LAG.

Task 3: Ensure all VLAN traffic successfully goes over the fa1/15 trunk and NOT the ether-channel trunk unless the fa1/15 trunk is down. Do NOT use backup interface to accomplish this.


Task 4: R1 and R2 should be put into VLAN 10 and should be able to ping each other fa0/0 interface. You must use the legacy vlan database command to create the VLAN.

Task 5: Ensure VLAN 20 traffic is never permitted to traverse the fa1/15 trunk should that trunk link become the active trunk link

Task 6: Ensure SW1 has the highest probability of always being the root bridge for VLAN 10, even if another switch is introduced into the network.


Task 7: Configure OSPF area 0 between R1 and R2. OSPF hellos should only be sent out their connected subnet interface ONLY. Ensure R1 loopback 0 interface can ping R2 loopback interface.


Task 8: Configure EIGRP 100 between the connected links of R1 & R3 and R2 & R3 ONLY. Ensure R3 REDISTRIBUTE its loopback 0 interface ONLY.

Task 9: Mutually redistribute between OSPF and EIGRP on R1 and R2. All routers (R1, R2, and R3) should be able to ping each others loopback 0 interfaces.


Task 10: Without using static routes or policy-based routing, ensure R2 is able to traceroute to R3 loopback 0 interface over its directly connected link. Don’t worry about affecting the optimal routing of other routes.

Task 11: You must deny R1 from being able to telnet to R2 only if R1 sources the telnet request from its fa0/0 IP address.


Bonus Task: on R2, Redistribute RIP into OSPF and RIP into EIGRP. Ensure you account for any potential loops. All routers should have full reachability to each other loopback 0 interfaces including R4 Loopback 0 interface.



11 Responses

  1. That’s great, I have just started looking at GNS3 – how did you make the switches, I though you couldnt’ do that in GNS3?



  2. You just need to add the NM-16ESW module to the router for the switch functionality. However, there are limitations. Do a quick google and you should find what you are looking for.

  3. It’s great idea!
    I wonder if you can post final configurations of this test.

  4. wow thanks a lot for sharing!

  5. Any hints on Task 3. I can’t say I have ever done this. Maybe I have.

    • I got it. Change the spanning-tree cost. Raise the port-channel above 19 or lower the f0/15 below 12. Is this correct?

  6. I have just passed my CCNA so this is probably out of my league. However I am curious. How can I force a switch to prefer a trunk link with a cost of 19 over a trunk link with a cost of 12?
    I know google is my friend, but I don’t seem to ask the right question.

  7. What a great idea… Ive interviewed candidates who didnt know how to show the routing table

  8. You should have a section stating what verification’s (show commands) you are using to grade the answers. There are a couple of ways you can answer a few of these questions. I suppose as long as the end result got you where you wanted you don’t care. I liked the test though it was a good deal of fun.

  9. ‘legacy vlan database command ‘ – lol. Good test?? who’s proficient in that EOL module.

  10. Absolutely brilliant idea, im studyin switch as my 1st np topic but see this as great to get my teeth into. Have got and am working through some lab docs too. Ive got 2×2950’s a 3550(emi ios) & 3x2610xm’s so forget gns3 this is goin “live” baby! (task 2 will hav to be L2 etherchannel tho, i take it that was always the intention?)… Any addional lab suggestions would be greatly appreciated XD

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: