Hi,
I was doing the end-of-chapter exercises in the DCN book for the chapter on designing an addressing scheme and noticed that they recommend using the reserved addresses for the internal networks. This included the frame-relay and ISDN links. How can you use a private address for a router ISDN or frame-relay interface? Unless I am wrong, both ISDN and frame-relay enter the carrier's switched network which is in the public domain so I would think that Internic assigned addresses would have to be used. Any input would be greatly appreciated.

Thanks,
Slacker71

PS. Does anyone else who has used or is using the DCN book feel like the chapters are a little thin on content. It makes it very difficult to know what is important to learn, so I have found myself going to the Cisco site and pulling up more in-depth information on many subjects. This is the first Cisco Press book I have used, are they all this way?

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Yes you are mistaken. When you use frame relay, say from your LA office to your Oakland office you have a router at both sites. Your circuit is in a private (not public) network going through the providers network (frame cloud). You pick the addressing scheme and they assign you a DLCI that maps to that ip address, you map the ip address to the dlci, a static entry or you use inverse arp that dynamically will do that for you. When you think of Public network you can pretty much say that is internet, like a VPN solution etc...

Hope that helps, I am really tired and cannot seem to get my thought on paper.

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Thanks Flash. After I posted I was going back over some of my CCCNA stuff and realized my mistake. Thanks for the explanation though, it was clear to me!

Slacker71

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