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Help - IP Problems

By it_admin ·
I have an IP only network (we connect to Corporate for email and internet access) and I'm running out of IP addresses. We have 127 addresses [ is the router to Corp.] We have NT four servers.

Does anyone know if/how I can use the existing 'real' IP addresses and the 'psuedo' addresses (192.0.0.x etc.)

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by zander In reply to Help - IP Problems

This isn't a registered address only to be used on a private network

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Personally ...

by kevinalexander In reply to Use

Personally I would use 10.x.x.x addresses, they are easier to work with and more flexible. They are reserved as well (like 192.168.x.x).

You can subnet, say, 3 segments with a number range
and subnet mask

Trust me - this is the best way!

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Author asks....

by it_admin In reply to Personally ...

I have 127 addresses, that are nearly all used. Is there any way I can use NAT or a proxy server to connect 20-30 PCs to my LAN using only one 'real' IP address?

They need IP for email and internet access.

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by Shanghai Sam In reply to Author asks....

I'm assuming you have 127 authorised internet addresses in use on your LAN - is that right?

If so, you really should change that quickly to a reserved range (suggest 10.x.x.x subnet 255.255.x.x). Why? Because unless you have a really good reason for doing it, it is a servere security risk for your network. Unless you have a real good firewall an intruder could very easily (just by using the IP address!) gain access to your network.

Once you have done that you can use NAT on a server connected to the internet to provide web access, etc.

Hope this helps

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You caught that last zero.... good eye!

by DBlizzard In reply to Use

Three sets of IP addresses are set aside by the Internet Assigned Numbers Authority (IANA). through through through
For information about private addressing, see RFC 1**8.

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Help - IP Problems

by Shanghai Sam In reply to Help - IP Problems

Can you do this yes. How is a different matter. How big is your network and how big do you see it growing? Are you responsible for only one part of the network or all of it? Do have control of the router to Corp? The first question will help you decide which private IP addresses to use. Class A is approx. 16.5 million hosts, B is - approx. 1 million hosts, C is - approx 64k hosts. Also, you will want to know how the network is segmented. The second and third question will help you figure out who you can call for help. If you manage the whole netwrok then a vendor or just yourself. If you manage just your section talked to your corporate network administrator. Now, the real how. If you controller the router then you can asign private IPs on your side and have the router keep the IPs seperated. If you do not control the router then a second network card in one of your NT boxes will do the trick. Set up the first nic tocommunicate to the router and the second to be the private networks new router.

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Author again...

by Shanghai Sam In reply to Help - IP Problems

Thank you all for your replys.

It's an extremely big organization (no-one seems to know too much) and I control one little bit (not including the router that connects directly with Corp.)

I have another server running sitting in my office, soI'll install NT (and a second NIC)on it.

Do I need any other software or does NT have everything I need?

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You will need more than NT

by mjervis In reply to Author again...

You will need more than NT. If you are going to accept all the mail for your part of the organization you will also need Exchange Server. The other thing you will need is Microsoft proxy server to share the internet connection with your users.

Questions to ask yourself first (mainly because your companies security lies on this) 1. Am I qualified to set this up myself? 2. Should I go with a linux flavor rather than buying all these microsoft licenses?

I am questionable of these questionsdue to the fact you asked if NT was all you needed. Your job may revolve around the security of the company data at that location. If thats true then I would really search for those answers.

I will not get into the proverbial NT vs. Linux war. What I will say is you need a system you know how to administer completely without leaving your company wide open to hackers and attacks.

Another observation is you may need some network training. The best thing may be hiring an outsider to come in and setup the server for you and have them teach you basic administration tasks before they turn the system over to you.

My answers may not always be the popular opinion, It may never be the answers you want to hear, But I would suggest you not throw away my answer or opinion. You may one day be looking at an unemployment line wondering if my answer was right.

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From Author

by it_admin In reply to You will need more than N ...

All of the things I am looking at are under Corp.'s Sercurity umbrella. They control everything and have it sewed tighter than the proverbial "duck's butt".

I have experience with NT servers (none with Linux), but I have never had to set up "dummy IP addresses other than using a cable modem with 1 real and 4 dummies.

Even the router to Corp. is internal as we have a physical cable connection between our building and our TV station and our main offices.

The PDC's address is and my sales dept. NT server has 2 NICs with and, the former address connects to the same switch as the PDC. I cannot get the PCs on the 10.x.x.x segment to see the 207.x.x.x segment.

The 10.x.x.x segment is running DHCP. I can ping each NIC from it's own side but I can't ping the 207.x.x.x segment from a PC.

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Author again

by it_admin In reply to From Author

I forgot to mention... the Exchange server is located at Corp. too and we have no problems getting our emails.

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