Re: WRED without fairq / cb-wfq ?

From: AK Singh (singh.anand@gmail.com)
Date: Thu Oct 28 2004 - 04:16:04 GMT-3

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
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
>
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