fast switching

david_r

I'm a little confused on fast switching. I'm reading through Cisco's "Configuring Switching Paths" off the doc CD and they say this in one section, "Fast switching allows outgoing packets to be load balanced on a per-destination basis."
then in another section it says, "Fast switching also provides load sharing on a per-packet basis."

As if I'm not confused enough, here's what they have to say about SMDS encapsulation. "SMDS fast switching of IP, IPX, and AppleTalk packets provides faster packet transfer on serial links with speeds above 56 kbps." and then they say, "Fast switching is not supported on serial interfaces using encapsulations other than HDLC."

huh?

EdTheLad

Fast switching uses a cache and switches per destination,meaning all the packets heading to the same destination will transverse the same link.Its not acurate load balancing.
Process switching load balances per packet, it doesnt use a cache so its not so fast.
CEF Zzzzzzzzz do a search on google.

cisco_trouble

If im not mistaken, "Fast Switching" and "Cisco express forwarding" and 2 different technologies. IP CEF is the new fast switching technology. CEF uses route caches the TCAM and CAM tables in the switch. It maos ip to mac to port and switches in that way. It is also done in hardware. The load balancing part i must check up on it...

david_r

Thank you for the reply. I have to wonder, did you actually read my whole question?