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atached route

Arjun Dabol
Level 1
Level 1

hello experts:

 

what is the meaning of "Having a  attached route in RIB " ? what is attached route ? does ii mean directly connected ?

 

Thanks

 

1 Accepted Solution

Accepted Solutions

Hi,

You probably mean this one:

https://tools.cisco.com/quickview/bug/CSCun29482

This statement basically describes a part of CEF operation. RIB (Routing Information Base) stands for a routing table, and "attached route" means a directly connected network that would be marked as C in the show ip route output. For these directly connected (that is, attached) networks, individual hosts in these networks are added to the CEF FIB with a netmask of /32. These entries would not be visible in the show ip route but they would be listed in the show ip cef output that shows the resulting FIB (Forwarding Information Base).

Best regards,
Peter

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5 Replies 5

Peter Paluch
Cisco Employee
Cisco Employee

Hello,

Can you describe the context in which this sentence appears? Perhaps include more text from the source in which this statement is written.

Best regards,
Peter

I read this line in some article:

"A /32 prefix  is present as a result of an attached route in RIB out of a multi-access interface."

Hi,

You probably mean this one:

https://tools.cisco.com/quickview/bug/CSCun29482

This statement basically describes a part of CEF operation. RIB (Routing Information Base) stands for a routing table, and "attached route" means a directly connected network that would be marked as C in the show ip route output. For these directly connected (that is, attached) networks, individual hosts in these networks are added to the CEF FIB with a netmask of /32. These entries would not be visible in the show ip route but they would be listed in the show ip cef output that shows the resulting FIB (Forwarding Information Base).

Best regards,
Peter

rglus
Level 1
Level 1

I believe the question is if an ATTACHED route means the same as a DIRECT route?

For example showing ip route table in a vrf (only showing 1 entry here)

10.78.18.128/25, ubest/mbest: 1/0, attached

I have googled like 20 word combinations to try to find an answer if they mean the same but I cannot find anything.

So for example in the VRF, you redistribute direct

router bgp XXXXXX
vrf XXXXXX:XXXX
address-family ipv4 unicast
redistribute direct route-map redist-direct-bgp

Is direct the same as attached?

rglus
Level 1
Level 1

why would Cisco denote the routes with a whole new word "Attached" if they are direct?