I need help with “Virtual Template “ & “ Leak-Map “ .

    I was going through some of the R&S technology labs and I found that they have used “ Virtual Template “ in few cases . It would be great if someone can tell me at what situations do we use  “Virtual Template “  ? Please help me with some reference books for this. Also i would like to know about “ Leak-Map “ . Do we often use these two commands in production environment?

Thank you


  • Praveenp,

    A virtual-template interface is usually used in these cases:

    1. PPP over Frame-Relay (PPPoFR)
    2. PPP over Ethernet (PPPoE) - the virtual-template is used on the server end
    3. In the Service Provider world you might see PPP over ATM (PPPoA)

    If you need authentication, multi-link, link quality control, or some other feature that PPP provides but the native protocol on the link does not provide, a virtual-template interface may help you achieve the goal.

  • A leak-map is used with doing summarization in EIGRP. It allows specific subnets to be leaked through to designated neighbors.



  • Praveenp,

    Leak-map is similar to the unsuppress-map that can be used with BGP summarization - knowing that these things exist and where to look them up can give you an edge in the lab.

    Also - remember that the CCIE Lab Exam does not necessarily test on best practices, or real-world situations.

  • Virtual Templates is a whole different story. As Darrell has mentioned it can be used in many places. I would recommend you to go through Frame-Relay section from Vol 1 where you will find scenarios in which they show you how to use it with PPPoFR. Also go through some later tasks from Bridging and Switching section where they must have presented examples on how to use it with PPPoE setup.

    Technically ATM is not on R&S blueprint so you can leave that part.

    As far leak maps goes it can be used in two major situation inside EIGRP.


    1. To Leak some specific routes out of summary

    2. WIth EIGRP stub routing configurations.


    Going through following documents will give you good idea.





  • Thank you all :-)



    With EIGRP under the sub-interface you do not have the option of "leak-map" that is where you have to use virtual-templates.

    Native Frame-relay does not support authentication, link qaulity..etc...there you have to use virtual-templates which is PPPoF...and alot more usage... do some search in google and go through volume workbook.





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