Thanks Tyson.  I almost posted the same question the other day since I found
the documentation on NVI less than clear, and I think you've explained the
piece that was confusing me.

So just to make sure I understand this, "domain based NAT" will translate
anything that starts with (config)# ip nat inside ... *only* on interfaces
configured with (config-if)# ip nat inside and will translate anything that
starts with (config)# ip nat outside ... *only* on interfaces configured
with (config-if)# ip nat outside.

For NVI, we just use (config)# ip nat source ... and it will translate
anything matching the specifications regardless of direction.

Also, NVI doesn't work with a route-maps, so if you need to translate a
specific set of source/destination networks or match on something more
complex, you would need to use a route-map and domain based NAT (even though
it seems be configurable when using NVI):
R8(config)#ip nat source route-map ?
  WORD  Route-map name

Any other circumstances you can think of that would require the use NVI vs.
domain-based NAT?  Otherwise, seems like NVI would actually be easier as a
general rule.
-Dave


On Tue, Jan 18, 2011 at 12:11 AM, Max Pierson <[email protected]> wrote:

> I like the new NAT format which I still need to learn a little more about
> it, but I wish Cisco would would make up their mind and stick with it.
>
> Tyson, I know you're aware of the PIX/ASA "access-list permits/denys" we
> mapped to the outside public and not the inside translated IP up until 8.3.
> WTF .... been that way for years .... but now they decide to change to the
> logic that I first "thought" I understood to make sense. Now it's all
> reverse of what i've been using the last 5 years. Go figure :)
>
> Anyways, enough ranting for the day. Tyson, thanks for the help earlier.
>
> Regards,
> Max
>
> On Mon, Jan 17, 2011 at 10:02 PM, Tyson Scott <[email protected]> wrote:
>
> > Also if you click on the vlecture link in Marko's signature I have a
> > vlecture on NAT on ASA and IOS and that should help with this concept as
> > well I believe.
> >
> > Regards,
> >
> > Tyson Scott - CCIE #13513 R&S, Security, and SP
> > Managing Partner / Sr. Instructor - IPexpert, Inc.
> > Mailto: [email protected]
> > Telephone: +1.810.326.1444, ext. 208
> > Live Assistance, Please visit: www.ipexpert.com/chat
> > eFax: +1.810.454.0130
> >
> > IPexpert is a premier provider of Self-Study Workbooks, Video on Demand,
> > Audio Tools, Online Hardware Rental and Classroom Training for the Cisco
> > CCIE (R&S, Voice, Security & Service Provider) certification(s) with
> > training locations throughout the United States, Europe, South Asia and
> > Australia. Be sure to visit our online communities at
> > www.ipexpert.com/communities and our public website at www.ipexpert.com
> >
> >
> > -----Original Message-----
> > From: [email protected]
> > [mailto:[email protected]] On Behalf Of Nilesh Mehta
> > Sent: Monday, January 17, 2011 6:32 PM
> > To: [email protected]
> > Subject: [OSL | CCIE_RS] difference between ip nat enable/ip nat inside
> >
> > I am not sure what is the difference between these two NAT commands. Can
> > any
> > one help to understand  what is difference between ip nat enable and ip
> nat
> > inside/outside command
> >
> > Example:--1
> > int fa0/0
> > ip nat inside
> > int s0/0/0
> > ip nat out
> > -------------
> > example--2
> > int fa0/0
> > ip nat enable
> > int s0/0/0
> > ip nat enable
> >
> >
> >  I know ip nat enable is new method of doing nat and create an NVI
> > interface
> > but my questions is,
> >  both commands are same ? can we use vice-versa  or there there some
> > situation where you can use only specific one ( I mean ipnat enable or ip
> > natinside/outside)
> >
> > Thanks
> >
> > Nilesh
> > _______________________________________________
> > For more information regarding industry leading CCIE Lab training, please
> > visit www.ipexpert.com
> >
> > _______________________________________________
> > For more information regarding industry leading CCIE Lab training, please
> > visit www.ipexpert.com
> >
> _______________________________________________
> For more information regarding industry leading CCIE Lab training, please
> visit www.ipexpert.com
>
_______________________________________________
For more information regarding industry leading CCIE Lab training, please visit 
www.ipexpert.com

Reply via email to