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TOPIC: Question on Nat example

Question on Nat example 15 years 2 weeks ago #55

  • tfs
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I really like the Nat subject on this site, but had a question on the last example in the Dynamic NAT (Part 1).

In this example, there are 4 different contractors - I assume from different companies - that are trying to get access Dynasofts network. Three of the networks are private and the 4th, Datapro, is a public network (

My question is, how is this traversing the internet (or dialup) with this public address. Is it connected via VPN or is it just for demonstration purposes and would also be Nat'd to the internet with some Private address?

I was curious as I was thinking of setting up a test setup at my house to play with different scenarios of the different Nat types, just to see it in action.

Also, is there there a way to do this without an expensive router (NT for example). I assume that most home Networks use the Nat Overload for their Nating. I have a couple of Linksys Routers, so that won't solve my problem and I really can't afford an expensive Cisco Router.

I was going to use my Network Observer Protocol Analyser to watch the packets and see what it does.

(I do love my toys).



Question on Nat example 15 years 2 weeks ago #56

  • Chris
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The entire NAT topic took more than 5 weeks of work in order to produce the result everyone reads [img]images/smiles/icon_smile.gifHence the details !

I had a quick look at the Dynamic part1 & 2 pages in order to try and see where your question came from, but failed to figure it out.

As you correctly noted, the example shows 4 different contractors or companies which connect to Dynasoft's network in order to gain access to the systems they need.

The example assumes that these connections are via peer to peer wan links. This means that each contractor has a router which is setup to dial directly into Dynasoft's router.

I supose this should have been clarified in order to avoid readers assuming that the connection might be over the Internet, cause it's not. The truth is that even if it was, there are very few things which would change, and one of these would be the network datapro has and this is because the network is not a valid routable network - Internet routers will not route to any to network-.

Lastly, the only way we would be able to use the same network, would be if it was being pumped through a VPN, in which case the Internet routers wouldnt see the encrypted packet/ip address the tunnel carried.

Now, coming to your second question, you can setup a similair network, i cant remember how good NT4 is with it, but Windows 2000 does offer such services, so you can set it up as a nat router between lan networks, which would work fine.

I hope the above helped clear your questions and thoughts!


Question on Nat example 15 years 2 weeks ago #57

  • tfs
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Not complaining. I think it is a great job. I was just confused as to the fact that the other 3 contractors had public addresses and Datapro had a public one. I didn't know if this was for illustrative purposes or a connection via VPN.

I haven't done anything with peer to peer Lan links, so not sure how that works. My confusion.

I have set up test routers with NT4 before, but I don't remember anything about NAT and if Win2K will do it, then I will use that.


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