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Does WS-X67XX line cards support by Sup-2T VSS?

Hi Guys:

i am a bit confused now.

,I read the document, and


Q.I have Cisco 6700 Series line cards today with Centralized Forwarding Cards (CFCs). Are these line cards supported in a Cisco Supervisor Engine 2T system?

A. A Cisco Supervisor Engine 2T system will support all Cisco 6700 Series line cards with CFCs.


So, As long as the 67XX line card is using CFC, it is compatible with Sup-2T.

I also find the IOS release note indicate the 6704-10G with CFC is supported by Sup-2T, but it require 512M memory.

The bug details is not disclosed.  So I further search what the default memory size of the WS-F6700-CFC is, then I found here says it is only supported by Sup720 and no memory upgrade option, which means must upgrade to DFC4, in another words, it is not compatible with Sup-2T


Centralized Forwarding Card (CFC) for use on WS-X67xx Ethernet modules. This daughter card is supported only by the Supervisor Engine 720. There are no memory options for this daughter card.

default memory: 256M

So my question is:

whether “WS-X6724-SFP with CFC” and “WS-X6704-10G with CFC” compatible with Sup-2T without upgrading to DFC4 daughter card, and do they support in VSS-2T?

Cisco Employee

Hi Jason,

indeed the documentation is poorly written and misleading.

The Sup-2T supports 6700 LCs equipped with CFC daughter boards but the fact that those can only have 256MB of DRAM represents a limitation under certain circumstances as described in CSCtn23893. The bug is about an issue related to ISSU. "Any LC with 256MB memory hard resets with ISSU runversion. A soft reset is expected. For the line card to soft reset a minimum of 512MB memory on the line card is required."

A CFC with 512MB of DRAM would not be affected by the bug but... those don't exist.

Unfortunately the documentation has not been updated in the right way with the info coming from the bug (I will write to the BU asking them to write this better).



At this time, from what I am reading, while the 47xx-CFC is supported on the 2T, it is not supported in VSS configuration.  Is that correct? 


Leo Laohoo
VIP Community Legend

Ummmm ... 6704 is not compatible to VSS, period.

6708 and 6716 are compatible to VSS, HOWEVER, 6708 is not compatible to Sup2T.  6716 is compatible to Sup2T as long as you upgrade the DFC card. 

not completely true.

6704 + CFC and 6704 + DFC4 are both supported with Sup2T and in both Standalone and VSS modes.

6704 are not supported as VSL links but in MEC configuration they are fine.

I assume that you were indeed referring to 6704 card as the 47xx's are LCs for Cat4k and obviously cannot be used on Cat6k.