I would like to understand how a C6K (fabric-only) line card with two fabric connections and no classic bus interface (to my knowledge) communicates with a classic line card which comes without fabric access like a Flex-Wan card. I do know how fabric-enabled card work which offer both connection types.
The SFM which has a connections to the XBAR and the the 32 Gig BUS, all of these cards also connect to the DBus and RBus.
So if if a packet comes into a DFC enabled card and no local switching decision is made the packet will traverse to SFM and up the BUS to SUP module by doing this all ports in the switch copy the packet.
The results of the lookup will be sent down the RBus which instructs what ports should flush the packet.
This is all accomplished because of the modes you configure, you will notice that if you have a mix of classic and SFM cards then the mode drops to flow-through or truncated hence the forwarding engine (Sup2/PFC2) only sees 64 byte packet headers (truncated-headers) Without the SFM in the system, the 32 Gbps bus and forwarding engine will receive the entire packet from fabric-enabled linecards - this utilizes more of the bus capacity.
The key difference in the DFC-enabled system is that a switching decision is made on the input module instead of centrally at the Supervisor Engine.
The only question/issue I would like to resolve is the point how the SFM connects to the chassis and indirectly to the other blades. From my knowledge the SFM does not connect to the legacy bus except to get power. Could you direct me to any pice of information about the D/R/C Bus connection of an SFM?
Hope this helps, i got this info on a gold partnet training.
Also bear in mind the fabiric only cards punt traffic towards the SFM which in turn punts it onto system (normal) BUS via the Medusa.
A critical component of the local-switch implementation is the connection point between the local system and the SFM. In the Catalyst 6500, this function is handled by an ASIC called Medusa. This ASIC is the interface between the local bus and the crossbar.
[toc:faq]The ProblemOn traditional switches whenever we have a trunk
interface we use the VLAN tag to demultiplex the VLANs. The switch needs
to determine which MAC Address table to look in for a forwarding
decision. To do this we require the switch to do...
[toc:faq]Introduction:Netdr is a tool available on a RSP720, Sup720 or
Sup32 that allows one to capture packets on the RP or SP inband. The
netdr command can be used to capture both Tx and Rx packets in the
software switching path. This is not a substitut...
IntroductionOSPF, being a link-state protocol, allows for every router
in the network to know of every link and OSPF speaker in the entire
network. From this picture each router independently runs the Shortest
Path First (SPF) algorithm to determine the b...