We're Sorry, Full Content Access is for Members Only...

If you like to keep on reading, Become a Member Now! Here is Why:

  • Learn any CCNA, CCNP and CCIE R&S Topic. Explained As Simple As Possible.
  • Try for Just $1. The Best Dollar You've Ever Spent on Your Cisco Career!
  • Full Access to our 597 Lessons. More Lessons Added Every Week!
  • Content created by Rene Molenaar (CCIE #41726)

 

393 New Members signed up the last 30 days!

satisfaction-guaranteed

100% Satisfaction Guaranteed!
You may cancel your monthly membership at any time.
No Questions Asked!


Forum Replies

  1. awesome lessons. especially the

    “EIGRP auto-summary will only create summary routes for directly connected networks, not for routes you learn from other EIGRP routers.”

    i just learned it here.

    thanks rene!

  2. Good to hear you like it! I think that’s one of the things that is important to know, most people assume EIGRP will just summarize anything when you use auto-summary.

  3. Rene
    this a great article and explaination

    thanks

  4. Hi Rene

    Thank you that was a useful lesson.
    There is an important thing that you didn’t explicitly mention and is important.

    • The eigrp router will only announce an auto-summary out an interface if the classful network of the interface is different from the classful network of the interface it learnt the network from. In other words if it has 2 interfaces and both are in the same network class, it will never send an auto summary out (this is how I understood the cisco info, haven’t labbed it).
      Cisco says it this way "When a router has multiple working interfaces, and those interfaces use IP addresses in different classful networks, the router advertises a summary route for each classful network on interfaces attached to a different classful network.

    What I took away from the lesson is:
    -A router will only send out auto-summaries of connected networks (never learnt)
    -A router will only auto-summarize between network classes.

    Thanks
    Raul

  5. Hi Rene
    I got this "EIGRP auto-summary will only create summary routes for directly connected networks, not for routes you learn from other EIGRP routers."
    But what about OSPF auto-summary route. Does it do the same thing ?
    Thank you so much .

5 more replies! Ask a question or join the discussion by visiting our Community Forum