From: Bill Greenwood (billgreenwood@xxxxxxxxxxxxx)
Date: Sun Feb 10 2002 - 14:25:35 GMT-3
When you configure the interface enter the "randon-detect" on the interface.
This will enable RED, then enter the "randon detect" again with the question
mark (randon-detect ?) and you will see that you now can enter the rest of
the commands for WRED.
----- Original Message -----
From: "Jon Carmichael" <jonc@pacbell.net>
To: <ccielab@groupstudy.com>
Sent: Sunday, February 10, 2002 1:43 AM
Subject: Playing with WRED
> I'm having lots of fun here trying to make WRED work. Following the book
IP
> Quality of Service, by Srinivas Vegesna for those of you who might have
the
> book or are interested in making this work. I'm struggling with the
> relationship between WRED and CBWFQ, and why I'm being forced by the IOS
to
> treat those two as the same, perhaps WRED is a subset of CBWFQ?
>
> I'm working an example similar to his on page 134, but not getting the
> results I would like. I've done this on a 2500 and a 4500 with the same
> result, and that is that it keeps thinking that I'm doing CBWFQ, when I
want
> to make WRED drop some packets. I'm setting my minimum-threshold to 2, my
> maximim threshold to 4 for all precedence levels, where I think I can
> generate enough tcp packets so force some drops, but the problem is that
my
> interfaces think it's CBWFQ as soon as I put a service-policy on them,
when
> what I thot I wanted is WRED.
>
> Of course RED, is not WRED, and if you do "random-detect" on the
interface,
> you don't get to mess with weights, but a service-policy, to follow the
> example in the book is coming up as CBWFQ. Even after I put
"random-detect"
> in my policy-map, I am still required to put a "bandwidth" before I can
set
> things like the "exponential-weighting-constant" or the "random-detect
> precedence..." Of course once I apply the policy-map to the interface
it
> pops up with a queueing strategy of CBWFQ, where I was hoping to see WRED.
>
> The relevant parts of my configuration are below..
>
> * * *
> class-map non-critical
> match access-group 101
> !
> !
> policy-map SET-WRED
> class non-critical
> bandwidth 8
> random-detect
> random-detect exponential-weighting-constant 3
> random-detect precedence 0 2 4 1
> random-detect precedence 1 2 4 1
> random-detect precedence 2 2 4 1
> random-detect precedence 3 2 4 1
> random-detect precedence 4 2 4 1
> random-detect precedence 5 2 4 1
> random-detect precedence 6 2 4 1
> random-detect precedence 7 2 4 1
> !
> * * *
>
>
> JONC
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