From: Lord, Chris (chris.lord@lorien.co.uk)
Date: Thu May 27 2004 - 08:04:56 GMT-3
I'm only a rookie but......
Whilst Brian's comment are absolutely correct, in practice, surely option 1 & 2 give the same result given that there is only an FTP class and a class-default. Non-FTP traffic would only get less than 10% if a third class was to be introduced later.
It's also my understanding that there are differences between the version of IOS you are using. I'm not sure when it changed (12.2 ish) but in earlier versions the bandwidth command "specified bandwidth allocation as a percentage of the max-reserved-bandwidth". In later version the bandwidth command "specifies bandwidth as a percentage of the underlying link rate". So....
Older IOS & Option 1 gives
FTP: 90% (BW) of 90% (MRB) = 81% of link speed
non-FTP (inc protocals and everything else) gets remaining 19% of link speed
Older IOS & Option 2 gives
FTP: 90% (BW) of 100% (MRB) = 90% of link speed
non-FTP (inc everything else) gets remaining 10% of link speed
Newer IOS and Option 1 and 2 gives
FTP: 90% (BW) of link speed
non-FTP (inc everything else) get remaining 10% of link speed
On the newer IOS the max-reserved-bandwidth command only seems to serve as a warning marker during configuration rather than affecting the maths. Or am I completely off-course here?
Regards,
C.
-----Original Message-----
From: Kenneth Wygand [mailto:KWygand@customonline.com]
Sent: 27 May 2004 06:18
To: Brian McGahan; ccielab@groupstudy.com
Subject: RE: bandwidth-percent in class-default
Hey Brian,
I see... FTP traffic can basically get more than 90% of traffic with my first configuration during congestion while other traffic would be guaranteed the other 10% of traffic during periods of congestion.
My real uncertainty lies in the "class-default". Does system-generated traffic (routing processes, etc) fall into this class or would that traffic potentially starve if all remaining bandwidth (to fill up 100%) was guaranteed in the class-default (of course this could only be done by changing the "max-reserve-bandwidth" value to 100%).
TIA,
Ken
-----Original Message-----
From: Brian McGahan [mailto:bmcgahan@internetworkexpert.com]
Sent: Thu 5/27/2004 1:08 AM
To: Kenneth Wygand; ccielab@groupstudy.com
Cc:
Subject: RE: bandwidth-percent in class-default
Ken,
Yes there is a difference. In the first configuration non FTP
traffic is not guaranteed bandwidth in the case of congestion. In the
second configuration, non FTP traffic is guaranteed 10% of the output
queue in the case of congestion.
HTH,
Brian McGahan, CCIE #8593
bmcgahan@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987 x 705
Outside US: 775-826-4344 x 705
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> Kenneth Wygand
> Sent: Wednesday, May 26, 2004 10:04 PM
> To: ccielab@groupstudy.com
> Subject: bandwidth-percent in class-default
>
> Is there a difference between the results of the following
configurations?
>
> My requirement is to reserve 90% of the interface bandwidth for FTP
and
> 10% for everything else. Note the explicit "bandwidth-percent"
> configuration command under the "class-default" my policy-map.
>
> <snip>
> OPTION 1:
> class ftp
> match protocol ftp
> policy-map 90forFTP
> class ftp
> bandwidth-percent 90
> interface s0
> max-reserve-bandwidth 90
> service-policy 90forFTP
>
> OPTION 2:
> class ftp
> match protocol ftp
> policy-map 90forFTP
> class ftp
> bandwidth-percent 90
> class class-default
> bandwidth-percent 10
> interface s0
> max-reserve-bandwidth 100
> service-policy 90forFTP
> </snip>
>
> Thanks in advance,
> Ken
>
>
_______________________________________________________________________
> Please help support GroupStudy by purchasing your study materials
from:
> http://shop.groupstudy.com
>
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Wed Jun 02 2004 - 11:12:17 GMT-3