Task 8.3

The answer for this task sets "frame-relay mincir 1536000", however in 8.1 we'd set "frame-relay cir 512000".

This raises two thoughts in my mind:

1. It doesn't make sense for the min-CIR to be greater than the configured CIR

2. Even if having a mincir > cir is valid, implementing this in this lab would break the requirement set in task 8.1, i.e. that the spokes have set CIR's and can only burst up to the access rate.

Am I missing something in my thinking?

Cheers.

 

Comments

  • Other Issue:

    according to configuration guide:

    Restrictions for LLQ with Priority Percentage Support

    Dropping Excess Traffic

    By default, when the bandwidth percent and priority percent commands are used to allocate bandwidth, the sum of the bandwidth percentage allocated to the high priority traffic and the bandwidth percentage allocated to the nonpriority traffic cannot exceed 99 percent of the total bandwidth available on the interface.

    The remaining 1 percent of the total bandwidth available on the interface is kept in reserve for the unclassified traffic and routing traffic, if any, and is proportionally divided among the defined traffic classes.

    error message received:

    Rack1R5(config-cmap)#POLICY-MAP OUT-R5-R3
    Rack1R5(config-pmap)#CLASS QUAKE-TO-VLAN3003
    Rack1R5(config-pmap-c)#PRIORITY PERCENT 100
    Sum total of class bandwidths exceeds 99 percent
    Rack1R5(config-pmap-c)#

    is there a way to configure 100 %?

    regards.

    Horacio.

     

     


  • Another mistake here is the SG's access-list is wrong. It states:

    permit udp host 154.12.5.100 154.12.3.0 0.0.0.255 eq 27960

    It should say the following because we are matching Quake traffic from the server which will use UDP port 27960 as a source port:

    permit udp host 154.12.5.100 eq 27960 154.12.3.0 0.0.0.255 


     

  • Hi all,

       Indeed the ACL is wrong, has been fixed for the May updates. For the "priority percent" command, depending on the IOS version running, it may accept 100% or 99% as the maximum. For the "frame-relay mincir 1536000" command, it is needed but you can type any value above 512000; here the line rate was chosen. When you configure "priority percent 99" it will pick 99% out of MINCIR, which by default is CIR/2; so in this case 99% out of 256000. Task requires to give that traffic maximum possible BW, so you need to make MINCIR at least equal to CIR, so that it can use 99% out of 512000;maximum is anyways (Bc+Be)*1000/Tc. So any MINCIR value above CIR is right, but the value itself does not make any difference.

    Hope it makes sense,

    Regards,

  • I used mincir 512000 and when I saw the SG I was shocked. Cristian, I understand your explaination but from a teaching perspective wouldn't it be better to use 512000 than 1536000?

    You guys have to realize we can be overwhelmed sometimes with the amount of knowledge we need to learn and to throw weird commands in just because it "would work" makes the student's job harder and more frustrating.

  • r5 access-list is still wrong, please update.  I am using v5.10.018 version

    It should be permit udp host 154.1.5.100 154.1.3.0 0.0.0.255 eq 27960

     

  • Aren't these access-list the same thing. What is the difference?

    permit udp host 154.12.5.100 154.12.3.0 0.0.0.255 eq 27960

    permit udp host 154.12.5.100 eq 27960 154.12.3.0 0.0.0.255

  • I used mincir 512000 and when I saw the SG I was shocked. Cristian, I understand your explaination but from a teaching perspective wouldn't it be better to use 512000 than 1536000?

    I was suprised too. What is the sense of setting mincir > cir value?

    It's against idea of mincir - router is supposed to lower packet rate on interface from mincir to cir if link is congested. Even if router allows to set mincir>cir, it is not effective, just take a look into output of sh policy-map int s0/0/0 command. It can be clearly seen, that router set mincir to cir value.

     

  • I agree with Malick Ndiaye.... also used permit udp host 154.12.5.100 eq 27960 154.12.3.0 0.0.0.255

     

    I hope the exam question would be a bit more direct wrt the server sourcing the traffic from this port or sending to the destination port ....

     

    note that based on ejeangilles question...they are indeed quite different....

     


    permit udp host 154.12.5.100 154.12.3.0 0.0.0.255 eq 27960

    permit udp host 154.12.5.100 eq 27960 154.12.3.0 0.0.0.255

     

    the first line permit traffic from server to destination on specified dest port...

    second line permit traffic from server with source port .... to destination.....

     

    note client server relation......

     

  • I just set "priority" in the policy-map (without a number or percent).  I was under the impression that using this command by itself will set strict priority for all traffic in this class.

  • guys ,

     

    if the router can send at line rate even if cir is lower than line rate , then i think it makes some sense to allow mincir = line rate . AS we are asked to allow max as possible.

    has some one did any labs ,which  shows that router can bump up their speed if min cir is > cir .?

    againt the idea though where it is intended to slow down from cir to mincir

  • Why not just apply old legacy "priority queueing" 

     

     

    Regards,

    Bruno Fernandes

     

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