http://www.cisco.com/univercd/cc/td/doc/product/software/ios112/ios112p/gsr/
cef.htm refers to the base of the CEF feature, David is spot on CEF uses a
Forwarding Information Base (FIB) to make IP destination prefix-based
switching decisions.
The FIB is conceptually similar to a routing table or information base. It
maintains a mirror image of the forwarding information contained in the IP
routing table. When routing or topology changes occur in the network, the IP
routing table is updated, and those changes are reflected in the FIB. The
FIB maintains next-hop address information based on the information in the
IP routing table.
Because there is a one-to-one correlation between FIB entries and routing
table entries, the FIB contains all known routes and eliminates the need for
route cache maintenance that is associated with earlier switching paths such
as fast switching and optimum switching.
Adjacency Tables
Network nodes in the network are said to be adjacent if they can reach each
other with a single hop across a link layer. In addition to the FIB, CEF
uses adjacency tables to prepend Layer 2 addressing information. The
adjacency table maintains Layer 2 next-hop addresses for all FIB entries.
Have you opened a TAC case, or contacted your account team ?
Regards
Frank Bruce
Consulting SE, NSP West
Cisco Systems Ltd
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-----Original Message-----
From: Miguel A.L. Paraz [mailto:map@internet.org.ph]
Sent: 10 February 2001 16:09
To: cisco-nsp@puck.nether.net
Subject: [nsp] CEF, BGP tables and memory
Hi,
128 MB RAM on my 7206 NPE-200 isn't enough to run CEF it seems, with two
full BGP views. I don't think I need CEF for performance, but I do want
CEF for uRPF.
When you turn on "ip cef", I believe that copies the entire BGP table to
CEF?
I only need the customer static routes to copied to CEF, is that possible
on 12.0.14(S) ?
--http://www.internet.org.ph The Philippine Internet Resource Mobile Voice/Messaging: +63-917-810-9728
This archive was generated by hypermail 2b29 : Sun Aug 04 2002 - 04:12:28 EDT