rib + fib & process switching ,cef


Just question in regard to the rib and fib & process swithching and cef. For example say we have ospf and eigrp on same router nothing else no statics. Does all routes i.e the topology table in eigrp and the link state table in ospf (i.e all routes best and worst of both protocol routes) populate the routers rib table. Then the routers fib table is made up of face off between routes in the ospf forwarding table vs routes eigrp routing table(i.e the best routes in both). With eigrp winning in default config because of the lowest admin distance and populating the fib tbale.  

Then difference between process switching and cef. Is that process switching ques and searches the rib table for the best route taking more time + processing. While cef works of the scaled down fib table speeding up the switching speed of the router??

Can someone confirm this is correct or explain?

BarepAssetsSys AdminAsked:
Who is Participating?
 
Otto_NConnect With a Mentor Commented:
The way I see it, the RIB is the combined routing table of both routing protocols (with AD already accounted for), while the FIB table is the specific forwarding table for the specific hardware configuration (containing the MAC rewrite info).

For a comparison between Process switching and CEF, look at http://www.cisco.com/en/US/tech/tk827/tk831/technologies_white_paper09186a00800a62d9.shtml.  It is a bit technical, but should help you with your questions.
0
 
Nayyar HH (CCIE RS)Connect With a Mentor Network ArchitectCommented:
Yes, I think I agree with you to an extent.
My understanding of the RIB is that it is seperate from the Routing Table and the RIB contains all *best* routes from individual routing sources. The best routes from the RIB populate the Routing Table with *best* routes. The FIB as you mentioned is a scaled down version of the RT which off-course is the overall best routes from all.
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.