Re: WRED without fairq / cb-wfq ?

From: Cisco Net (network.cisco@gmail.com)
Date: Thu Oct 28 2004 - 15:44:42 GMT-3


Guys,
I am so confused now...
so on non distributed systems should i enable fairq for wred ?
Please help and verify...
Cert

On Fri, 29 Oct 2004 00:44:00 +0800, Kian Wah Lai <kian_wah@qala.com.sg> wrote:
> I checked the Knowledgenet Implementing QoS course and it stated
> 'Nondistributed WRED cannot be combined with fancy queuing - FIFO queuing
> has to be used'.
>
> ----------------
Regards,
Kian Wah
Singapore Cisco User
> Group
http://www.sgcug.org/
3 routers and one PIX rental at SGD2/hr or
> USD1.30/hr
>
>
>
> Jongsoo.Kim@Intelsat.com wrote:
> I think WREQ or queue-limit can be used with Fair Queue, which is of
> course
subject of critic audit.
Fair Queue defines queue depth
> (congestive-discard-threshold, DF=64 )and
WRED or Queue limit define how
> packets should be dropped when the queue
depth exceeds. With WRED, the
> packet will be dropped based on WRED feature
and with queue limit, the
> packet will be dropped based on FIFO

By the way, I am taking lab tomorrow
> and hope this doesn't show up.

Regards

Jongsoo

-----Original
> Message-----
From: AK Singh [mailto:singh.anand@gmail.com]
Sent: Thursday,
> 28 October, 2004 3:16 AM
To: John Matus
Cc: Cisco Net; Group Study
Subject:
> Re: WRED without fairq / cb-wfq ?

I am still not clear if fair queuing
> needs to be enabled before
configuring WRED (say on ethernet
> interface)

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fqos
_c/fqcprt3/qcfwred.htm#22292

The
> documentation and example doesn't say that. I also observe that
both
> fair-queue and random detect seems to be mutually exclusive and
if you
> configure one other is gone, In fact if "random detect" is
configured, IOS
> won't let you configure "fair-queue". See the log
below. Can someone clear
> this doubt for me:

R2#sh running-config interface e0/2
Building
> configuration...

Current configuration : 216 bytes
!
interface Ethernet0/2
> ip address 169.1.27.2 255.255.255.0
 no ip mroute-cache
> half-duplex
end

R2#c
Enter configuration commands, one per line. End with
> CNTL/Z.
R2(config)#interface ethernet 0/2
R2(config-if)#fair-queue
>
R2(config-if)#^Z
R2#sh running-config interface e0/2
*Mar 6 05:47:03.976:
> %SYS-5-CONFIG_I: Configured from console by console
R2#sh running-config
> interface e0/2
Building configuration...

Current configuration : 228
> bytes
!
interface Ethernet0/2
 ip address 169.1.27.2 255.255.255.0
 no ip
> mroute-cache
 half-duplex
 fair-queue
end

R2#sh queueing interface
> e0/2
Interface Ethernet0/2 queueing strategy: fair
 Input queue: 0/75/0/0
> (size/max/drops/flushes); Total output drops: 0
 Queueing strategy: weighted
> fair
 Output queue: 0/1000/64/0 (size/max total/threshold/drops)
> Conversations 0/1/256 (active/max active/max total)
 Reserved Conversations
> 0/0 (allocated/max allocated)
 Available Bandwidth 7500
> kilobits/sec

R2#c
Enter configuration commands, one per line. End with
> CNTL/Z.
R2(config)#int e0/2
R2(config-if)#ran
R2(config-if)#random-detect
>
R2(config-if)#^Z
R2#sh queueing interface e0/2
Interface Ethernet0/2
> queueing strategy: random early detection (WRED)
 Exp-weight-constant: 9
> (1/512)
 Mean queue depth: 0

 class Random drop Tail drop Minimum Maximum
> Mark
 pkts/bytes pkts/bytes thresh thresh prob
 0 0/0 0/0 20 40 1/10
 1 0/0
> 0/0 22 40 1/10
 2 0/0 0/0 24 40 1/10
 3 0/0 0/0 26 40 1/10
 4 0/0 0/0 28 40
> 1/10
 5 0/0 0/0 31 40 1/10
 6 0/0 0/0 33 40 1/10
 7 0/0 0/0 35 40 1/10
 rsvp
> 0/0 0/0 37 40 1/10

R2#sh running-config interface e0/2
Building
> configuration...

Current configuration : 232 bytes
!
interface Ethernet0/2
> ip address 169.1.27.2 255.255.255.0
 no ip mroute-cache
 half-duplex
> random-detect
end

R2#c
Enter configuration commands, one per line. End
> with CNTL/Z.
R2(config)#in
R2(config)#interface
> e0/2
R2(config-if)#fa
R2(config-if)#fair-queue
Must remove RED
> configuration first.
R2(config-if)#^Z
R2#
*Mar 6 05:47:56.596:
> %SYS-5-CONFIG_I: Configured from

On Wed, 27 Oct 2004 22:16:14 -0700, John
> Matus <jmatus@pacbell.net> wrote:
 
> now, a question that has come up is weather you have to specify a queue
> size
 
> when you configure 'fair-queue'. from what i'm told the default queue
 size
> is zero so unless you create queues the whole thing doesn't
> practically
work......
anyone care to comment on this?

Regards,

John D.
> Matus
MCSE, CCNP
Office: 818-782-2061
Cell:
> 818-430-8372
jmatus@pacbell.net
----- Original Message -----
From: "Cisco
> Net" <network.cisco@gmail.com>
To: "Group Study"
> <ccielab@groupstudy.com>
Sent: Wednesday, October 27, 2004 7:13 PM
Subject:
> WRED without fairq / cb-wfq ?

 
> Hi
Is fairq or cb-wfq is a requirement for wred... ?
So far i was thinking
> this is the requirement until somebody mentioned
 me
 
>
> it is not a requirement.So i am seeking help here to verify this..

1) Can i
> enable wred on an ethernet interface without changing the fifo
 to
 
>
> fairq
 queueing. I tried and it dows not complain but i am not whether i
am
> doing right
 or wrong.
2) I know that in MQC i can enable on class-default.
> Also the default
q is fair q here
 How about if i have a class with cbwfq
> (bandwith) and LLQ
(priority). Can i use
 wred on these classes...

Thank
> you for your
> help..
Regards
Cert



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