[c-nsp] A simple access list question

Oliver Boehmer (oboehmer) oboehmer at cisco.com
Tue Feb 8 05:42:08 EST 2005


>      I have failed to find a written detail regarding the difference
> in impact of the access-list below , assuming i have networks
> 192.168.131.0 ,132.0 , 133.0 etc.
> 
> -- What impact these lists will make in actual production if written
> incorretly. 
> 
> right way is ---
> permit ip 192.168.131.0 0.0.0.0255 192.168.200.0 0.0.0.255 any
> 
> wrong would be --
> permit ip 192.168.0.0 0.0.255.255  192.168.200.0 0.0.0.255 any
> 
> In eigrp advertisement i m advertising
> network 192.168.131.0
> network 192.168.132.0 etc
> 
> Any written document stating its impact ? or any suggestions will be
> appreciated.

So this ACL is used as a routing filter? Apart from the fact that you
would advertise the wrong networks, you will see no difference
(performance-wise) between the ACLs. 
Unless you are using *huge* ACLs, control-plane performance is usually
of no concern.

	oli



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