The RFC states that you want to filter traffic that contains source address not 
legitimately in use by the customer network.

Generally that would include  0.0.0.0/8,10.0.0.0/8,127.0.0.0/8, 172.16.0.0/12, 
192.168.0.0/16, 224.0.0.0/4,and 240.0.0.0/4, but it's not limited to these 
addresses.  You should also include the address space in use by the internal 
network.  This makes sense since the address space used internally should not 
be seen as the source in packets from the outside.

As RFC 3704 states, on possible solution for this would be uRPF.  If you use 
uRPF you dont need to worry as much about the addresses that you use.  If you 
use ACLs on ingress you do.  The reason you've probably seen differences in the 
ACLs probably relates to the networks used in the examples.

Regards,

Brandon Carroll - CCIE #23837
Senior Technical Instructor - IPexpert
Mailto: [email protected]
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On Apr 26, 2010, at 6:36 AM, Kingsley Charles wrote:

> Hi all
>  
> Can someone please let me know, the addresses for RFC 2827/3704 that should 
> be followed. I see differences, in the way they
> are implemented in various sites.
>  
> The RFCs also does not mention specific addresses for RFC 2827/3704 as it 
> does for RFC 1918/3330.
>  
>  
> With regards
> Kings
> _______________________________________________
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> visit www.ipexpert.com

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