Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

Cisco 6500 Switch Achitecture


Got confused by reading too many documents regarding the PFC,MSFC,SP and RP.

PFC - Policy feature card and know the use of it. 

MFSC - Multilayer Switch Feature Card and know the feature of it.

For Sup 720: How the PFC and MSFC are integrated. Are both come across single hardware card ?

What is SP and RP?

MSFC is done RP ?

is SUP manages SP ?

What is Daughter card ?

How many IOS are required in cisco 6500 Swtich. Like Sup OS, and IOS ?

We have Flash memory in SP and in RP as well external memory - disk0?  what are the default settings on these flash.


I just asked all my query in a unformatted manner. May be you can explain in a order in order to understand. One or two line is enough to explain as i read lot of stuff, So i can easily relate to that.


Looking for a Crispy answers. Will rate for sure.




VIP Super Bronze

Here is good doc explaining

Here is good doc explaining sup 720 architecture and all the parts. There is also 2T which is the latest for the 6500 series.


Super Bronze

DisclaimerThe Author of this


The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.


Yes, PFC and MSFC are both on sup720 line card.


SP is switch processor (L2).  RP is route processor (L3).


Sup is supervisor, the "brains" for the chassis.  It's doesn't manage the SP it is encompasses the SP.  (E.g. the sup720 card.)


A daughter card is a small circuit card/board that you plug into a socket on another card.


Today, only one IOS is used on 6500s.  However, in years past, two were used; one for the SP (CatOS) and one for the RP (IOS).  The former is known as running in "native" mode, the latter as running in "hybrid" mode.


Regarding defaults for the different memories, default for what?  Sizes or boot usage?  Size defaults have changed with later hardware revisions.  Default boot sequence depends on running mode and config register boot option settings.  Also with right IOS, right config reg setting, you can specific boot strings in configuration.  (Booting options, I believe, are also impacted by boot ROM version, which is upgradable.)

Hall of Fame Super Blue

GanJust to add to Joseph's


Just to add -

put simply the PFC is responsible of the data of forwarding plane ie. the actual L2 and L3 switching of centrally forwarded traffic.

If the linecard has a DFC (Distributed Forwarding Card) then it offloads forwarding of the data to the actual linecard itself.

The MSFC is responsible for the control plane eg. STP/VTP etc. at L2 and buiding the L3 IP routing table. Once the IP routing table is established it then builds the FIB (Forwarding Information Base) which is downloaded to the PFC and any DFC enabled linecards.

Here is a link to a document that goes into a lot more detail on their roles -