Help in Understanding of cisco express forwarding

[Rahul Chauhan]

Hi greetings, I am having trouble in understanding the FIB table. Please help me out on this. Below is the image of that table. Thanks

[Peter Paluch]

Hello Rahul,

What is it exactly you would like to ask about? The FIB table shown in your snapshot is a classic one from a multilayer switch - nothing unexpected there. Is there anything specific you are looking at?

Best regards,
Peter

[Rahul Chauhan]

Hi Peter,

I would like to know what it is, what does it represents every detail about that snapshot like which IP is droping and received and attached and interface what does all this means, in short understanding FIB table. Help me on this.

thanks

[Spooster IT Services · Accepted solution]

Hi Rahul,

CEF uses a 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.

drop means that any packet that match the destination ip address or subnet in that entry will be dropped.
receive means that any packet that match the destination ip address or subnet in that entry will be forwarded to the CPU for processing.
attached means simply that the ip address or subnet in that entry is locally connected.