[nsp] stupid NAT tricks

Stephen J. Wilcox steve at telecomplete.co.uk
Sun Feb 29 10:30:25 EST 2004

On Sat, 28 Feb 2004, Christopher J. Wolff wrote:

> Hello,
> I have a Ethernet sub interface on router A that uses an overloaded NAT pool
> for internet access.  I have another Ethernet sub interface on router B
> (connected to A) that has a server I want a device on subinterface router A
> to connect to.  However I don't want it to use the overloaded nat pool.  I
> set up a static route however it appears that the devices behind the router
> A subinterface want to use the NAT pool even if there is a static route
> between the two devices.

Perhaps I'm misunderstanding.. if the server isnt in the A-interface then it 
wont be subject to being NATed, if a device on A tries to connect to the server 
on B it shouldnt be NATed either, assuming that you havent defined the B 
interface as a 'nat outside'.

(Also, as Gert says, the static route has nothing to do with how NAT operates. 
If there is a reason why this is being NATed other than misconfiguration then 
you can modify your acl to exclude the translation or if its complicated use a 
route-map with more sophisticated acls on)


> Here's what it looks like
> Router A---------LAN------------Router B
>    |						|
> NAT pool A------------|		File Server
>    |			    |	
> Subint    |
> 			    |
> 			Internet
> Any suggestions would be appreciated.  I read something on the cisco site
> about a 'no-payload' statement which seemed to apply to this situation but
> it wasn't clear how.  Thank you.
> Regards,
> Christopher J. Wolff, VP CIO
> Broadband Laboratories, Inc.
> http://www.bblabs.com
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/

More information about the cisco-nsp mailing list