Thanks, Edison - very useful link.

Having read the info on that link I now have another question. I have a CAT 6513 with a WS-X6724-SFP module in slot 1 (non-fabric enabled slot obviously). First, I'm kind of surprised that it is even working there. It must be running at a slower line rate w/o the fabric connection through the Sup 720.

Would it even do any good to add a DFC-3B to this module in its current location or do I need to move it to a fabric enabled port (9-13) for this to even do any good?

Thanks for your help - that was a very insightful link!

Jim

Jim,

WS-X6724-SFP when upgraded to a DFC3 enabled module, will be a dual-fabric module.

On the link, Table 1, dual-fabric modules will need to be on 9-13.

If the module was to be a single fabric module, yes there are some out there, then you can use any slot.

All 6513 slots have fabric connections with sup720, but only slots 9-13 have dual fabric connections.

As to why WS-X6724-SFP works in slot1, from http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/product_data_sheet0900aecd801459a7.html:

• Backplane connection: Connects to the switch fabric using dual full duplex 20 Gbps switch fabric channels (40 Gbps total), a single 20 Gbps channel is supported by the WS-X6724-SFP

DFCs provide local, on card, forwarding (dCEF), i.e. more PPS. Not exactly the same issue as bandwidth available to the card.

Jim

Just to add to Joseph's point. A Sup720 delivers a 720Gbps switching fabric.

Just to complicate things when Cisco talk of module connections they don't use full duplex figures ie.

a 6708 has 2 x 20Gbps connections to the switch fabric which is 40Gbps total. But at full duplex this

is 80Gbps.

So for a 6509 chassis a Supervisor 720 can provide 40Gbps to each slot ie. 9 x 40 = 360. To get the full

duplex figure you then double that number ie. 360 x 2 = 720.

For a 6513 chassis you cannot have every slot providing 40Gbps because this would work out as

13 x 40 = 520 x 2 = 1040Gbps.

But as previously stated the Sup720 can only provide 720Gbps. So the first 8

slots can only provide a 20Gbps connection maximum to the switch fabric and then 9-13 provide 40Gbps ie.

8 x 20 = 160

5 x 40 = 200

160 + 200 = 360 * 2 = 720

So as Joseph states the WS-X6724-SFP is still connected to the switch fabric but as it only supports one 20Gbps

connection it can go in any slot.

Jon

Jon and Joseph,

Good catch.

I missed the footnote on

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/product_data_sheet0900aecd801459a7.html

Table 1 about 6724 being single fabric.

__

Edison.

Thanks - so just to follow up on this. I can leave the 6724-SFP in slot 1 and upgrade it with a DFC3b and I will get full performance?

(I don't need to have that module installed into a dual fabric slot on the 6513 slot 9-13)?

Thanks,

Jim

Jim,

That's correct. All slots in the 6513 support single fabric modules such as 6724-SFP.

__

Edison