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 529 Lessons. More Lessons Added Every Week!
  • Content created by Rene Molenaar (CCIE #41726)

 

265 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!


Tags:


Notable Replies

  1. Hi Rene, What if you don’t know the number of hops of your neighbor router. What is going to be the configuration or is there any replacement for ebgp-multihop command ? Thanks

  2. Venus,
    In this situation, you can do two things:

    1. (config-router)#neighbor 10.10.10.10 ebgp-multihop 255

    2. Run a trace route from your router to the neighbor. Take the hop count from that. I usually pad it out by about three.

    Method #2 is the more desirable one, fyi.

  3. Hi Rene

    I have a question about load balancing with respect to routing. Here we have this static routes doing the load balancing for BGP messages. What kind of load balancing this is, is it per packet basis or something else?
    Also does this load balancing concept same for all routing protocols?

    R1(config)#ip route 2.2.2.0 255.255.255.0 192.168.12.2
    R1(config)#ip route 2.2.2.0 255.255.255.0 192.168.21.2

    Thanks
    Palani

  4. andrew says:

    Rohitendu,
    As the statement indicates, the default behavior of BGP is to choose only one best path. In order to do this, there is a somewhat complicated best path selection process - depending on how you count, it is 13 steps long! What the maximum-path command does is to tell BGP to stop at a certain point during that best path selection process, and basically say, "if you get this far in the selection process, then consider the paths equally good and use them both."

    In reality, it is rare for this feature actually to be used, because it stops the selection process pretty deep in the list. In order for multiple paths to be used, all of the following characteristics of the path must be equal:

    1. Weight
    2. Local Preference
    3. Local Origination Status
    4. AS Path Length
    5. Origin Code (i,e,?)
    6. MED (metric)
    7. Same IGP metric to exit points

    FYI:
    Here is a very detailed Cisco document that talks about BGP path selection, and how multi-path fits in:
    http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13753-25.html

  5. beanj says:

    after I follow your guide, I have that :

    S       2.2.2.0 [1/0] via 192.168.21.2
                    [1/0] via 192.168.12.2

    this routing table have installed in routing table since we have finished static route. then I tried BGP configuration, I got this message

    %BGP-5-ADJCHANGE: neighbor 2.2.2.2 Up

    but in routing table is the same, therefor what is benefit of BGP in this scenario?

Continue the discussion forum.networklessons.com

46 more replies

Participants