Re: CEf adjacencies

Hi,

Based on my understanding:

Null Adjacency - Packets will be dropped, by switching to null0 interface

Discard Adjacency - Packets will be silently discarded

Drop adjacency - Packets will be droped, generally used when unsupported
feature configured

Thanks,
Srinivas

On Thu, Jul 2, 2009 at 8:53 PM, Santiago Enciso
<senciso_at_infocenter.com.py>wrote:

> Hello, What is the difference between Null, Discard and Drop adjacencies?
> They seem to do the same.. Null0 is well known but the other 2?
>
>
> Packets of This Adjacency Type
> Receive This Processing
>
> Null adjacency
> Packets destined for a Null0 interface are dropped. Null adjacency can be
> used as an effective form of access filtering.
>
> Glean adjacency
> When a router is connected to a multiaccess medium, the FIB table on the
> router maintains a prefix for the subnet rather than for the individual
> host
> prefixes. The subnet prefix points to a glean adjacency. A glean adjacency
> entry indicates that a particular next hop should be directly connected,
> but
> there is no MAC header rewrite information available. When the router needs
> to forward packets to a specific host on a subnet, Cisco Express Forwarding
> requests an ARP entry for the specific prefix, ARP sends the MAC address,
> and the adjacency entry for the host is built.
>
> Punt adjacency
> The router forwards packets that require special handling or packets sent
> by
> features that are not yet supported in conjunction with Cisco Express
> Forwarding switching paths to the next higher switching level for handling.
>
> Discard adjacency
> The router discards the packets.
>
> Drop adjacency
> The router drops the packets.
>
>
>
> http://www.cisco.com/en/US/partner/docs/ios/ipswitch/configuration/guide/cef
> _overview_ps6350_TSD_Products_Configuration_Guide_Chapter.html#wp1054829<http://www.cisco.com/en/US/partner/docs/ios/ipswitch/configuration/guide/cef%0A_overview_ps6350_TSD_Products_Configuration_Guide_Chapter.html#wp1054829>
>
>
> Thanks Santiago E
>
>
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Received on Thu Jul 02 2009 - 21:30:22 ART