[RRG] FIB cache?

[András Császár (IJ/ETH) <Andras.Csaszar@ericsson.com>]

Hi!
On the Saturday seminar there was a discussion that only a few prefixes are responsible for majority of the traffic, while a lot of prefixes generate no or very minimal traffic. Someone had a comment that this speaks for having a FIB cache.

I thought there is already a cache in the hardware. Could we clarify how the routes (forwarding entries) are (or are not) cached? What tables/structures are stored in generic memory, what is stored in the linecard in a fast memory?

I think to know what is the difference between RIB and FIB. I am, however, at this moment not that sure when someone says "forwarding table", it equals to FIB or not. And is the "forwarding table" already maintained in the hardware on the line card (e.g. in a CAM), or it is still a software based representation.

Can someone bring some light into this? Because I think the caching comment is quite valid.

BR,
András