General discussion


Multiple Public IPs

By matt ·
Hi, I have spent many an hour now trying to find information out about this and have got nowhere so maybe somebody here can shed some light on the matter.

At present I have an SBS2003 machine with 2 nics one nic is the local area connection ( and the other is connected directly to a dLink DSL 300T adsl modem via ethernet. Firstly I believe this is a problem because the modem is assinging the public ip to the nic, i am told it should be assigned to a router then the nic should take an address such as (or whatever the router is configured to ) then forward traffic to the nic from the router using NAPT.

Maybe a new router to replace the modem?

This has only come about because of mt enquiry into multiple public ips.

My ultimate goal is to purchase multiple ips from my isp and have them route to another client connected to the Lan side card of sbs2003 box.

So I would like to know firstly if i do need a new router and if so what type would you recommend and after i have bought the router and the extra ip addresses where abouts do i configure this feature in sbs2003??

Any input would be great :-)


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by BFilmFan In reply to Multiple Public IPs

You should have a router or switch. The domain controller (SBS 2003) box should plug into one port of the switch and the DSL modem should be plugged into another.

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by CG IT In reply to Multiple Public IPs

well if you have the premium edition of SBS then you have ISA Server and you should install ISA. ISA is your perimeter firewall. If you have the standard edition, then BFilmfan is correct. You need some form of protection from the internet and a router will do the trick.

A modem isn't a router unless you get a all-in-one-box modem/router from your ISP. If that is the case, then you have to forward ports for public services to the SBS box. Email comes to mind as well as OWA and Remote Desktop.

For multiple public IP addresses, you need a router that can handle multiple addresses. A Sonicwall TZ 170 can do this and a Symantec 320 can handle 2 with one being a fail-over.

ISA server Enterprise Edition can handle multiple public IP addresses and multiple segments [multiple NICs].

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by wlbowers In reply to Multiple Public IPs

Multiple ip addresses are needed if you have several machines tied to the modem through a switch.

This will provide each machine with an internet ip address. Each will have direct accessability with the internet.

If you hook up a router to the modem. Then you can connect a couple of hundred machines to the router and they will be nat translated to the internet through one ip address.

The problem with this is that they are a translation as far as addressing goes.

The router will not replace the modem, it will connect between the modem and a switch.


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Maybe your modem already has a router built into it.

by crp In reply to


There is a possibility that your modem already has a router built into it. My DSL modem has one.

To find out, fire up your web browser, and copy the following into the location field, then hit enter.

You may have to change the ending number by one or two increments possibly to find the configuration page for your modem's router if it has one. If it has a built in router that should take you to it's configuration page interface, and you will be able to change settings to your liking.

Later, Ray Parrish

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