From: Scott Morris (swm@emanon.com)
Date: Tue Dec 28 2004 - 01:46:51 GMT-3
I'm not entirely sure I'd agree with that logic. When you use the bandwidth
command in your policy for any class, you are reducing the amount of
available bandwidth. That available bandwidth is used for:
1 - Any remaining classes in a policy
2 - Class-default
If you then go to reserve a finite amount for class class-default, you are
really disregarding why this equation is used, but not necessarily hindering
it. If you chose a bandwidth amount for the class class-default that was
greater than 25% of the interface's bandwidth (e.g. more than the
non-"available" stuff), then you should see a decrease.
Otherwise the router is likely thinking "hey, if you want to reserve
something I've already set aside, knock yourself out"....
Now, bear in mind, I don't pretend to understand the thinking of IOS
programmers! But that would seem to be the likely scenario in my warped
opinion. Perhaps I've had too much eggnog though!
Happy Holidays!
Scott Morris, MCSE, CCDP, CCIE4 (R&S/ISP-Dial/Security/Service Provider)
#4713, JNCIP, CCNA-WAN Switching, CCSP, Cable Communications Specialist, IP
Telephony Support Specialist, IP Telephony Design Specialist, CISSP
CCSI #21903
swm@emanon.com
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Bob
Sinclair
Sent: Monday, December 27, 2004 10:33 PM
To: David Duncon; ccielab@groupstudy.com
Subject: Re: Class class-default
Hi David,
When I reserve bandwidth for a class and apply that policy to an interface,
I should see the Available Bandwidth parameter decrease from 75% (default
max-reservable). Each time I reserve more bandwidth in an applied policy I
should see Available bandwidth (show interface) correspondingly decrease.
This did not happen when I entered the command to reserve bandwidth for
class class-default, further suggesting that the command is not effective.
HTH,
Bob Sinclair
CCIE #10427, CCSI 30427, CISSP
www.netmasterclass.net
----- Original Message -----
From: "David Duncon" <david_ccie@hotmail.com>
To: <bsin@cox.net>; <ccielab@groupstudy.com>
Sent: Monday, December 27, 2004 8:58 PM
Subject: Re: Class class-default
> Appreciate your feedback, Bob.
>
> As I did not quite get your point (attached clip bellow) , can you please
> elaborate ?
>
> <clip> it does not decrease available bandwidth on the interface. <clip>
>
> Cheers
>
> - David
>
>>From: "Bob Sinclair" <bsin@cox.net>
>>To: "David Duncon" <david_ccie@hotmail.com>,<ccielab@groupstudy.com>
>>Subject: Re: Class class-default
>>Date: Mon, 27 Dec 2004 08:17:17 -0500
>>
>>David,
>>
>>I would say definitely option 1. Is the bandwidth command really
>>effective in class class-default? On my box it takes the command, but it
>>does not show up in the output of "show policy-map interface," and it
>>does not decrease available bandwidth on the interface.
>>
>>HTH,
>>
>>Bob Sinclair
>>CCIE #10427, CCSI 30427, CISSP
>>www.netmasterclass.net
>>
>>----- Original Message ----- From: "David Duncon" <david_ccie@hotmail.com>
>>To: <ccielab@groupstudy.com>
>>Sent: Monday, December 27, 2004 2:54 AM
>>Subject: Class class-default
>>
>>
>>>Hi Group,
>>>
>>>I got a Q on MQC 'c class class-default behavior. And appreciate your
>>>guidance on this.
>>>
>>>On production network, let us consider that we have end to end L3 MQC
>>>policy which primarily aimed to protect Business critical apps such as
>>>Voice and Citrix and bundled every other traffic type such as File
>>>transfers , HTTP and Emails ..etc in to a common default class with
>>>random detect feature enabled. Since there is a bit of concern on the
>>>email (MS Exchange & Lotus Notes Domino) traffic with in a default class
>>>as we are seeing some drops there. So If we were to segregate &
>>>prioritize email traffic from the rest of default class traffic , then
>>>which of the following options is the better way to go. Either to leave
>>>the email traffic with in class class-default and assign a guaranteed
>>>bandwidth or to segregate email traffic in to separate class-map with in
>>>policy-map. The reason I am asking this Q is to understand any negative
>>>impacts the NON time sensitive email traffic can bring in to policy maps
>>>processing where already time sensitive traffic types (Voice & citrix)
>>>are being serviced.
>>>
>>>
>>>Option 1:
>>>=================
>>>
>>>Policy-map data
>>>
>>>Class voice
>>>Match access-group xxx
>>>Priority xxx
>>>
>>>Class citrix
>>>Match access-group xxx
>>>Bandwidth xxx
>>>
>>>Class email
>>>Match access-group xxx
>>>Bandwidth xxx
>>>
>>>Class class-default
>>>Random detect
>>>
>>>Option 2:
>>>==================
>>>
>>>Policy-map data
>>>
>>>Class voice
>>>Match access-group xxx
>>>Priority xxx
>>>
>>>Class citrix
>>>Match access-group xxx
>>>Bandwidth xxx
>>>
>>>Class class-default
>>>Random detect
>>>Bandwidth xxx ---------------------------------------> emails are bundled
>>>together along with file transfers & HTTP traffic with in class default.
>>>
>>>
>>>And my Qs are :
>>>
>>>1) is there any way where we can create 2 class-maps with in class
>>>class-default , one for email and the rest for all default traffic ? If
>>>yes is there any benefit in doing that ?
>>>
>>>2) or is it safe for me to create another class-map for email and slot
>>>that in with policy-map itself along with voice & citrix and dedicate
>>>certain amount of bandwidth to it.
>>>
>>>3) Thirdly , what is the between a class class-default with a bandwidth
>>>command and one with out a bandwidth command. And also what is the
>>>difference between a class class-default with a random detect command and
>>>one with out it. Though I do aware the functionality of congestion
>>>avoidance techniques such as WRED and RED , I was in the impression that
>>>besides configuring random detect , you need to map it to a relevant DSCP
>>>code which underlines a certain level of drop probability. In other
>>>words, you are telling the policy engine on what type of traffic you want
>>>her to drop should she pick up any early congestion warnings.
>>>
>>>
>>>Any feed back is much appreciated.
>>>
>>>- David.
>>>
>>>_________________________________________________________________
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>>>http://ninemsn.seek.com.au?hotmail
>>>
>>>_______________________________________________________________________
>>>Subscription information may be found at:
>>>http://www.groupstudy.com/list/CCIELab.html
>>>
>>
>>
>
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