Member Avatar for Firebird2010

Hello everyone! Sounds like I am begging huh! Well I been researching this now for almost a 3 weeks now. Only recourse is to hire someone in which we have no money to do so! I am new to this group.

I need to get (2) server systems up and running for this church web server and email server.

Ok so here is the big picture situation. I do NOT know much about router configs other then the basics of gateway and static IP and dynamic IP address simple stuff. My problem is that I have a ATT modem service to are area that will only allow a certain modem gateway to be used. It has a DHCP server built into the gateway, impossible to disable. I checked and double checked with ATT Uverse. I have 8 static IP addresses they gave me. I will make up these addresses just so you can follow along here.

Some History and background:
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I can USE (1) LAN Card off the mother board and/or add a 2nd LAN card in the PCi slot. My computer is new and fast and has 4 gig of ram and plenty of space. I doubt this is a hardware or software issue. More or less a Router setup and TCP/IP setup and DHCP problem.

used to be my Dynamic IP address. Supposely this could change at any time and renew. Always stayed the same no matter what they said about Dynamic Ip addresses changing.
Why do I even mention this? Well strange as it may be..when I do a "what is my IP address" out from any desktop or LIVe linux machine disc DVD guess what I get? You would think I would get one of the static IP addresses I assigned or have of the 5. But I get the old dynamic address of above there (Note: I am making all these addresses up for example sakes but they do follow the logical patterns)


So this would come into my Uverse router and the DHCP server of my Uverse would give out thru to any desktop computers in the church. The gateway to enter the modem was 192.168.1.254.
Next....we purchased a set of IP static addresses:
We shall call them : these fake (8) here
thru
gets hard wired into the Uverse Modem as the new gateway address. (Why? No idea its just how Uverse sets it up)
is the Broadcast OUT
is the Broadcast IN
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So I am left with (5) Static IP adx's to give to my (2) servers here.
So Microsoft Small Business Server 2008 will go on (or .72, or 73 or 74 or .75 doesnt matter really) Linux Server Fedora 10 same thing. So we will pu that on address
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Here is the problem. When I attempt to setup any Server, either Linux or Windows, it tells me. I have a DHCP server ALREADY on the network (its telling me the address of the gateway every time) so please disconnect from the DHCP and then hit continue with the setup. And this makes perfect sense to me. The server wants to create its own DHCP server and spool out its own addresses. I get that.
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How can I solve this problem since I can NOT shut off my DHCP server on the Uverse gateway modem? Does anyone have a simple step by step solution? I can offer up any details on my gateway router options if you ask. And I guess I can inject another router or LAN card in between my server and gateway as well. So there are options here.

Or a web page site with details on this? Thank you so much for any help and God Bless! You can email privately or post here. Whatever you would prefer. I accept emails. :)

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  • Latest Post Latest Post by hughv

Dani AI

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As described, the real problem isn’t the servers — it’s that the ISP gateway is both doing NAT and advertising DHCP that you cannot turn off. As hinted, the clean, reliable fix is to put a router you control behind the ISP gateway (or ask the ISP to put the gateway into IP‑passthrough/bridge mode). That lets your equipment own the internal DHCP and lets you map the static public addresses cleanly to your servers.

Practical steps (long‑term solution):

  1. Obtain a small router that supports a static WAN and either 1:1 (static) NAT or IP passthrough / DMZ.
  2. Ask the ISP to either route your static block to your connection or enable passthrough so your router can take a public IP.
  3. Connect your router WAN to the ISP gateway. Give the router one of the static public IPs (or let the ISP deliver it). Put your LAN on a private subnet (eg. 192.168.x.x) and enable DHCP there.
  4. Put your servers on private static IPs and use the router to 1:1 NAT a public IP to each server, or forward the required ports (HTTP, SMTP, etc.). This prevents the ISP DHCP from interfering with server setup and keeps internal DHCP under your control.

Shorter / no‑budget workaround:

  • If you cannot change hardware or ISP settings right away, keep the servers on private addresses and use the ISP gateway’s port forwarding to reach them from outside.
  • For Windows Small Business Server installs: temporarily isolate the server network during installation (disconnect the ISP gateway or unplug other network segments) so no other DHCP is present; install SBS as the only DHCP/DNS, then reconnect and move DHCP to whichever device you choose.

Notes and cautions: an 8‑address allocation is typically a /29 (5 usable hosts), so confirm which IPs are usable and which are the network/gateway/broadcast. For mail servers, arrange PTR/reverse‑DNS with the ISP for the sending IP. Keep exposed servers behind a firewall, patch OS/services promptly, and avoid giving servers direct Internet addresses unless you need to.

Recommended Answers

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Member Avatar for hughv

If you don't get any help here, try the Tech Support Guy Networking forum:

Member Avatar for Firebird2010

If you don't get any help here, try the Tech Support Guy Networking forum:

Thanks huhgv. I appreciate your link there.

Do you have any ideas or clues where I should google or start to solve this problem? Do you think I explained it enough in detail? If anyone has any questions please ask. No worries here, I am pretty easy going and appreciate any help. :)

Member Avatar for hughv

I'm far from an expert, but something looks wrong here.
I don't see any need for the fixed IP addresses.
The IP is the IP of your modem, and that's as it should be. The DHCP server would then hand out the 192.x.x.x addresses to the computers on your LAN. As far as it staynig the same, that's pretty common nowadays, but, eventually, it will change (See "lease Time").
So, with my limited knowledge:
Forget the fixed addresses.
Disable the DHCP server on the gateway.
Use the addresses handed out by the Modem.
I'm not a server guy, but I used this procedure to set up my second router (On the same network), and I think you'll find that's the right track.
Good luck.

Member Avatar for Firebird2010

I appreciate your comments there.

1.) can NOT disable the modem DHCP. It is hard coded into the eprom chip of the gateway. Impossible to change with Uverse as the ISP.

2.) If a customer uses a dynamic IP address and the lease expires then what??? Also who else is on this dynamic IP. Maybe they use it for many users and split it. Not sure if thats possible but one thing is for sure. The IT consultant they hired previously insisted on them getting static IP addresses for the (2) servers they will use for the Churches office and audio/ video media area. So lets just assume I am stuck with using these IP static's

Member Avatar for hughv

Dynamic IPs are not shared with anyone. Your ISP only has so many, so they change them as needed. No affect on you at all.
I've been assuming you have a router (The Gateway), but maybe I'm wrong about that. What's the exact configuration-the modem connects directly to the computer?
No router? Get one, with as many ports as you need.

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