is it possible to do conditional NATing

sivakondalarao · ‎08-20-2006

Hi,

We have OSPF network.

From our network to business partener we have two exit paths with different IP addressing scheme.

Our servers will communicate with business partener servers themselves (There is option to specify destination IP in our server application, i.e, only one destination IP)

If you see the diagram server is reaching gateway (which is local router), if there is any option to decide the exit path locally at router, then we can provide redundancy to reach business partener servers.

Otherwise we have to manully change destination IP in all our 200 servers two reach 2 business partener servers.

I am looking for this kind of solution:

Our server will use some x.x.x.x destination IP to reach business partener server irrespective of exit path1 network or exitpath2 network.

Local Router where our server is located has to poll exit path1 network. If that is reachable, Router has to change x.x.x.x destination IP to 10.134.23.x

If that is not reachable and exit path2 is reachable, Router has to change x.x.x.x destination IP to 10.132.23.x

This is our goal. Purpose is we need not to change destination IP in our servers.

Looking for your suggestions...............

Regards

SKRAO

vijayasankar · ‎08-20-2006

Hi Siva,

Depending on the setup we can try something to achieve something close to what you are intending. However i would like to know more about the setup.

1) Why you have 2 different IP for the destination server at Business Partner. Is it the same server with 2 different IPs.

I dont understand this point.

If exit path1 and exit path2 are leading to same business partner, then the servers at business partner should also be having the same ip address. is it not? .

Explain more on this point to understand the scenario better.

2) Is the destination servers are directly connected to the routers and exit path1 and exit path2?

Policy based routing decisions can be done easily, which manipulates the next hop based on reachability of some destination ip address.

Have a look at this url.

http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chapter09186a0080457bcc.html

For me it looks like this is possible. All you have to do is configure PBR with tracking option on your next and configure policy based NAT in routers at Exit path1 and exit path1 to change the destination address.

If you provide more information as requested, we can work this out.

-VJ

vijayasankar · ‎08-20-2006

Hi Siva,

Additional thougts..

You can very well configure both the PBR ( with tracking option) & the Policy based nat in the same router ( the servers default gateway).

All you have to do is configure PBR with tracking option in this router.

1) Create on tracking for 10.132.23.x ip. if only it is reachable set the next hop appropriatly.

2) Create another tracking for 10.134.23.x ip. if only it is reachable set the next appropriatly.

On the exiting interface of this router, you can configure NAT and do the translation based on the route-maps.

For policy based NAT, you can refer to the following URL

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

HTH

-VJ

vijayasankar · ‎08-21-2006

Hi Siva,

Get back to us with more details, so that we can work this out.

-VJ

sivakondalarao · ‎08-22-2006

Hi Vijay,

Customer has changed his network design.

Regards

SKRAO

sivakondalarao · ‎08-21-2006

Hi Vijay,

We have typical security setup.

I am saying 10.134.23.x and 10.132.23.x destinations.

Frankly to say they two are not actual destination IPs(IPs before so many Network Address Translations)

Our Intranet is extended to so many locations.

As I told you two exit paths, they two are from our Intranet two different locations to Partener two locations which two are having Interconnectivity.

Our Intranet is running with OSPF.

Briefly:

Our company is having so many branches.

via two branches we can reach our partner two branches.

One is DR site to another one.

If I give destination IP 10.134.23.x in server application, data will reach to branch 10.134.23.x through OSPF from there it will go to partner main branch.

If 10.134.23.x branch is down, I am manully specifying 10.132.23.x in server application.

So through OSPF, now the data reaches 10.132.23.x branch, through that setup it can reach partner backup site.

I think now you are clear about our setup.

My plan is to eliminate manual changing of IP addresses in Server application.

It should be happened automatically, to reduce down time.

I am also drawing small figure for your better understanding.

Finally one query do you belongs to tamilnadu?

are you working in WIPRO?

Regards

SKRAO

vijayasankar · ‎08-21-2006

Hi Siva,

Few more queries i have.

How is the connectivity from your router towards the Wan Cloud.

Do you have direct connectivity to routers at exit path2 and exit path1?

I was checking on this and this looks like possible to me, Based on the previous URLs posted.But need to check the same for your setup.

Update me on the above queries...

Best Regards

VJ