eigrp and CIR over Frame-Relay

hi all

when we configure the interfaces bandwidth over frame relay, we multiply the number of PVC into number of lowest CIR.

so if we have three CIRs

one is = 1000MB

second = 100MB

third = 10MB

 

the lowest CIR is 10MB

multiply by 3: 10 x 3 = 30MB

30MB will be configured on the multipoint interface.

 

so what that will achieve for us ?

 

thanks,

Comments

  • If you have multiple PVC on the single physical link & configured EIGRP on each PVCs, EIGRP will devide the bandwidth as per the number PVC that you have. Lowest bandwidth is referenced in order to effectively allocate the available bandwidth to all PVCs.

    HTH

  • if you see this picture

     

    image

     

     

     

     

     

     

     

     

     

     

    if R4 wants to send massive traffic to network behaind R1, here the link is 1000MB.

    but on R1 we have to configure the interface linked to the frame-relay to 30MB only (lowest multiply by the number of PVCs).

    is not that a problem ?

    means we are limiting all the high connectivity links that we connect with them !

     

    thanks,

  • Hi,

    The lowest bandwidth is referenced in order to avoid possible congestion in that scenario where you have single physical link & multiple PVCs. If all the bandwidth is eaten by the single PVC, other will starve & packets get dropped. So, it should allocate the entire bandwidth as per the number of PVC referencing lowest bandwidth.

    Hope this helps!

  • JoeMJoeM ✭✭✭

    if R4 wants to send massive traffic to network behaind R1, here the link is 1000MB.

    but on R1 we have to configure the interface linked to the frame-relay to 30MB only (lowest multiply by the number of PVCs).

    is not that a problem ?

    means we are limiting all the high connectivity links that we connect with them !

    Hi Oudmaster,

    I think you are talking about bandwidth pacing.

    This calculation is only in regards to the needs of the EIGRP protocol (50% by default) -- not the actual bandwidth we can use for each PVC.

    The end result of this example is that EIGRP will limit itself to 5Mb per PVC.

     

    In my opinion, the higher bandwidth today has far outgrown this 50% allocation.   EIGRP does not need that much "bandwidth" for its updates and communications. This can be adjusted with the following command:

             interface x/x

                     ip bandwidth-percent eigrp 100 <1-999999>

  • JoeMJoeM ✭✭✭

    if you see this picture

    About a third of the image is offscreen.   Try this.   Edit your post, and drag a corner of the JPEG.  This will allow it to fit ino your post.

  • check the picture now ?

     

    thanks,

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