Section 4.3 OSPF Stub Area - IEWB Vol 3 v4.1

Hello all,

Not sure if I am mistaken on this, but I believe there is an error in Section 4.3 (OSPF Stub Area) of Lab 1 of IEWB Vol 3 v4.1.

First off, the diagram depicts that SW1's f0/21 interfaced is to be on Vlan C, OSPF 3 and be a OSPF Stub and neighbor with R5. While F0/21 is not being used (as in other typical physical wiring topologies between SW1 and SW4 (F0/19-21 and F0/19-21), it is clearly not possible to have F0/21 of SW1 be a Native Routed port and connected to R5. That would be possible if R5 was connected to SW1's F0/21, but it is not. R5's E0/1 interface is connected to SW3. Problem is that SW3 is not the switch that should be in OSPF Area 3 (and Vlan 57) with R5. While I have configured SW3's F0/5 in Vlan 57 and R5's E0/1 port has the ip address, the only thing I am thinking is that this is clearly a typo what should have been requested is an SVI interface 57 on SW1 with the ip address of That is the what I have configured temporarily so that I could move on completing the rest of the lab tasks. Again, as I mentioned earlier, if R5 was connected to SW1 on port F0/5, then I could make F0/5 on SW1 a Native Routed port and configure both devices with their ip addresses per the diagram.  But that is not the case.

Anyhow, I hope someone can clarify that this in fact is an error. I will be in total shock if I am wrong. 

Thanks and I hope I am making sense here since it is 1:00 a.m. now.



  • I came across the same issue.  Kind of hard to miss this problem.  Fail.

  • Hi,

    I run into the same problem.

    I wasted around an hour trying to figure out what I did wrong!

    Finally I said maybe i didn't go wrong, maybe the workbook was wrong.

    I had to create an SVI with the ip address

    But I need to make sure if there is another way to let R5 and SW1 form an OSPF adj without creating the SVI.

    Cause in the solution guide, they simply enabled OSPF on both devices, without modifying anything!!!!!

    Do you have any update on this problem? 

  • Okay, I'm the 4th person to mention this and still no response from INE staff regarding if this is an error or an omission in the solution guide.


    Fantastic support guys.

  • I agree that this looks weird. Looks like the diagram is incorrect and also maybe the task should be updated. Did you report this as an error through your members account?

  • It is all possible.  One just has to map the physical topology correctly.  The diagram just does not depict the intermediate layer 2 infrastructure that is traversed between the two routed ports, which is quite typical.

    SW1 routed port fa 0/21 is physically connected to SW4 fa 0/15.

    Rack1SW4#sho run in fastEthernet 0/15
    Building configuration...

    Current configuration : 96 bytes
    interface FastEthernet0/15
     switchport access vlan 57
     switchport mode dynamic desirable

    then vlan 57 traverses then from SW4 to SW2 to SW3 to R5's routed port.

  • Totally agree with Dennis.  I just did this lab and at first was scratching my head as to why Fa0/21 on Sw1 was in up/down state. I referenced the physical topology diagram and noticed it connected back to Fa0/15 on Sw4.  Looked at Sw4 port fa0/15 and it was turned off.  So i no shut it and perfect.   I'm learning to pay attention to everything that is provided to me such as physical connectivity topology diagrams. 

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