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New Member

nat..............

Dear guys,

I have a simple query. I am to implement the internet solution in our company. We have got dedicated lease line to the service provider. We have another router for our intranet routing only. There the default gateway is our internet router. In the internet router the default gateway is the service provider's router. This is the simple scenario. Now we have a pretty large network comprises of global IP. My query is if I run nat then how will those global IP's in our intranet will communicate with their valid peers in the internet. For e.g we have 64.0.0.0 network and also microsoft has 64.0.0.0 network. How will hotmail communicate with our IP? If it is not possible then what is the remedy??

Thanks in advance.....

surajit

2 REPLIES
New Member

Re: nat..............

Well, it is possible, this is called an Overlap NAT configuration, but I dont suggest it. Here is how it works: When you type hotmail.com on your browser, a dns query sent out and comes back over your NAT router, when the NAT router detects responded IP address is within your local network, it performs an "Outside" nat, and modifies DNS response so that hotmail packages to be forwarded directly to the NAT router itself. A wise solution, but no way out if you try to reach hotmail using its IP address.

Bestway to solve this problem is to use the Private address space assigned by IANA, namely 10.0.0.0/8, 172.16.0.0/16 to 172.31.0.0/16 and 192.168.0/24 to 192.168.255.0/24

Overlapping NAT is a solution if there is no way to re-address local network.

Regards,

Cagri

Gold

Re: nat..............

Hi,

You could also try DNS Doctoring :

Read the following url: http://www.cisco.com/warp/public/110/alias.html

HTH

Jay

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