Re: Excluding a subnet from natting - route-map vs access-list

Note 2
The advantage of using route-maps is that under the match command you can
have more options other than source IP address. For example, under the
route-map, match interface or match ip next-hop can be specified. By using
route-maps, you can specify the IP address as well as the interface or the
next-hop address to which the packet is to be forwarded. Therefore,
route-maps with NAT are used in a scenario where the subscriber is
multi-homing to different ISPs.

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a0080093fca.shtml

 --
Garry L. Baker

"With sufficient thrust, pigs fly just fine..." - RFC 1925

On Sun, May 15, 2011 at 4:51 AM, Radioactive Frog <pbhatkoti_at_gmail.com>wrote:

> Folks,
> In below scenario where I am excluding 192.168.1.0/24 from NAT - in what
> scenario I'd use route-map?
> Noticed, I am not tweaking any metric or anything.
>
> Task# exclude 192.168.1.0/24 from NAT
>
> My understanding is both solution will work but easier one is solution#2
> without route-map. Save time in typing :)
>
> what are your thoughts?
>
> --------------- Solution#1----------------
> ip access-list extended NAT
> deny ip 192.168.1.0 0.0.0.255 192.168.2.0 0.0.0.255
> permit ip any any
>
> route-map POLICY-NAT 10
> match ip address NAT
>
> ip nat source route-map POLICY-NAT interface s0/0 overload
>
> interface f1/0
> ip nat inside
>
> interface s0/0
> ip nat outside
>
> ----------Solution#2---------------
> ip access-list extended NAT
> deny ip 192.168.1.0 0.0.0.255 192.168.2.0 0.0.0.255
> permit ip any any
>
> ip nat source list NAT interface s0/0 overload
>
> interface f1/0
> ip nat inside
>
> interface s0/0
> ip nat outside
>
>
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Received on Sun May 15 2011 - 06:17:42 ART