From: Swan, Jay (jswan@sugf.com)
Date: Tue Jun 26 2007 - 12:49:56 ART
If you don't put traffic into a particular queue with CBWFQ, it goes
into class-default. This includes routing traffic. Thus, it will get
whatever type of queueing you have set for class-default.
Under the default (25% non-reservable), then up to 25% of your bandwidth
is reserved for class-default. If you don't have other traffic in
class-default, then your control traffic will be protected.
However, it's possible that you could have lots of other traffic in
class-default as well, at which point control traffic would be subject
to the same drop rules as other traffic in class-default (that is, if
it's not already protected by pak_priority, as already discussed).
Make sense?
Jay
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Gregory Gombas
Sent: Tuesday, June 26, 2007 8:05 AM
To: Kamal Dissanayaka
Cc: Group study
Subject: Re: CBWFQ and pak_priority
I'm still not clear on what role max-reserved-bandwidth plays in
protecting the routing protocol traffic.
Isn't 25% of interface bandwidth reserved for control plane traffic by
default?
If so do you really need a separate class to reserve bandwidth for
routing traffic?
Or is that only necessary if you set max-reserved-bandwidth to 100%?
Thanks again for your replies.
On 6/25/07, Kamal Dissanayaka <kamalasiri@gmail.com> wrote:
> Hi Greg,
>
> My understanding is pak_priority applies for locally sourced packets
with
> cs6, please correct me if I am wrong. As an example most of the IGP
traffic
> is locally generated and span only one hop. On the other hand BGP
traverse
> through network and you need to specially assign them to a queue.
>
> Please have a look on bellow link.
>
>
http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_
guide09186a008022564f.html
>
> Best Regards
> Kamal
>
>
> On 6/26/07, Gregory Gombas <ggombas@gmail.com> wrote:
> >
> > I was wondering if you need to specify a seperate class-map for
> > routing protocols.
> >
> > According to the following doc:
> >
>
http://www.cisco.com/en/US/tech/tk543/tk544/technologies_tech_note09186a
0080094612.shtml
> >
> > On some platforms you need to specifically assign to a queue:
> > "In other words, on the Cisco 7500 series, if an output
service-policy
> > is attached to the interface, then the packets are classified with
> > respect to the classes in that policy, and the pak_priority packet
is
> > placed at the end of the chosen class queue. If the pak_priority
> > packet does not match any user defined class, then it is placed at
the
> > tail of the class-default queue.".
> >
> > What is the rule of thumb regarding routing protocol QOS?
> >
> >
>
This archive was generated by hypermail 2.1.4 : Sun Jul 01 2007 - 17:24:51 ART