# Someone Help Me! Cable Modem + Hub + Router



## JustinTD (Dec 4, 2005)

Ok, heres what I want to accomplish:
I am a running a game server. In the interest of loading balancing, I would like to run 2 game server computers. However, I am behind a router, and this doesn't seem to work. The software connects to both game servers, but clients can only connect to 1 of them (which happens to be the one i put in the DMZ from the router, and is also the client login/character server). So, I have 3 IP's allowed by my ISP. What I wanted to do is put the client/character/game server direct to the cable modem via a hub, and then connect the router to that hub also. That would in theory give me 1 computer outside the router and the rest inside. Then I could setup the 2nd game server inside the router network in the DMZ and everything SHOULD be hunky-dory. Problem? This didn't work. When I did it I could only get the computer to get and IP, router refuses to grab one. Here's how I set it all up:

Cable Modem -> Hub Uplink Port
Hub Port 1 -> Router WAN Port
Hub Port 2 -> Computer

When that didn't work, I tried this:

Cable Modem -> Hub Port 5
Hub Port 1 -> Router WAN Port
Hub Port 2 -> Computer

With the above, teh Computer was able to get an IP, I switched back to the first setup and was able to keep the IP when renewing, but the router was still not able to get an IP, so I tried the below:

Cable Modem -> Hub Uplink Port
Hub Port 1 -> Router Port 1
Hub Port 2 -> Computer

Cable Modem -> Hub Port 5
Hub Port 1 -> Router Port 1
Hub Port 2 -> Computer

Neither of these yielded any results.

Now, here's the hardware we are working with:
Motorola SB5100 Cable Modem
D-Link DI-624 Wireless Router
Intellinet 5 Port SOHO Hub (I have the LinkSys 5 Port 10/100 Hub/Switch coming in ... but won't have it for a week or so).

Recommendations?


----------



## MoralTerror (Nov 19, 2005)

To have both servers behind the router you would have to use a different external port for the 2nd one. You then need to map any traffic on that port to port 80 on the 2nd server


----------



## JustinTD (Dec 4, 2005)

you failed to understand. See if i could open the firewall up for the ports i would need, 6110-6118 and 4000, i would be all set, problem is, unless o put the computer on the DMZ no computers can connect. Also, the problem isnt so much that, as it is why doesn't thr router and the computer gran IPS from the cable modem if I have 3 external IP's available and only 1 in use?


----------



## Volt-Schwibe (Jan 12, 2003)

well, if you have three external ip's supplied by your internet provider, then you don't need a router to share them.

what i mean is, the router is going to always grab a single ip, and share it across all the computers connected to it.

if you want computers (1), (2), and (3) to each have an ip, they need to not be behind a router at all. 
(however, you can also disable the DCHP features of your router, or, you can type the DNS settings directly into each computer's setup panel, and that way, they will see past the router.)

it should look something like this:


----------



## JustinTD (Dec 4, 2005)

WaltSide said:


> well, if you have three external ip's supplied by your internet provider, then you don't need a router to share them.
> 
> what i mean is, the router is going to always grab a single ip, and share it across all the computers connected to it.
> 
> ...


right, which is what i did more or less. I plugged 1 computer and the router into the hub along with the cablemodem as described in teh first portion of this thread. this should give the router an IP and the computer an IP ... essentially having only 2 IP's used. One game server would be behind the router, the other outside the router.


----------



## Volt-Schwibe (Jan 12, 2003)

i'm still not seeing why you are using a router.

i am starting to think i can't really help.


----------



## johnwill (Sep 26, 2002)

Why don't you plug both game servers into the switch connected directly to the modem, and then the WAN port of the router into the switch?


----------



## JustinTD (Dec 4, 2005)

Ok let me get as specific as I can. Here's the setup I started with:

Cable Modem -> Router -> 3 Desktops, 1 Server.

I have a private domain, 3 client systems (1 wireless), and a wireless laptop. All of which need to have internet. This is why I have the router. Now, the game server setup is like this, first lets make a key:

C1 = Computer 1, my main desktop I use.
C2 = My fiance's wireless desktop
C3 = Game Server 1
S1 = Domain Controller (and Gamer Server 2)

Now, when someone needs to connect to C3 for playing a game, they use ports 6110-6118 and 4000. I opened those ports in teh router, and found people could not connect. So I put C3 into the DMZ, and viola! it worked. I setup S1 as the 2nd Game Server. When people connect to C3, it performs load balancing and tries to send a request to S1. Users cannot connect to S1 as it is not in the DMZ. So, I had this idea, if I put a hub before the router, I could put C3 on the hub directly, thereby giving it another external IP, I could then put S1 (while behind the router) in the DMZ allowing connections to that system. So it looks like this now:

Cable Modem -> Router -> C1, C2 (wireless), C3 (DMZ), S1

I wanna do this:

Cable Modem -> Hub -> C3, Router -> C1, C2 (wireless), S1 (DMZ)

Problem is, as I said in the first post, When I do the above, I can't get the router to draw an IP. Does the hub have to be a switching hub for this to work? If so, that might be the problem, the hub i am trying with is a BNC 10MB hub... but I do have a LinkSys Hub/Switch 10/100 coming.


----------



## johnwill (Sep 26, 2002)

A plain hub should work, not sure why it's not handling this. I'm guessing that you can't really get three IP addresses, that's the only thing that springs to mind. If you connect three machines directly to the hub, and the broadband modem on the other side, do you get IP addresses assigned for all of them? If not, this is the basic issue.


----------



## JustinTD (Dec 4, 2005)

problem solved, it appears the 3 licenses i am allowed are modem issued, IE the internal DHCP on the modem is supposed to issue IP's ... wont work for what i need...


----------



## Volt-Schwibe (Jan 12, 2003)

if i'm not mistaken, no matter how you do it, the only way to get three external ip addresses through one cable line is by modem issued ip's.


----------



## johnwill (Sep 26, 2002)

If that's the case, why won't the solution with the hub connected directly to the modem, two game servers and the router WAN port connected to the hub work? They're issuing the three IP addresses, and if they're available, this should function fine.


----------



## Volt-Schwibe (Jan 12, 2003)

unless you like your cable bill so much you want two more.

because the only other way i know of this ever working, would be to have 2 more actual peices of coax running into the house, each to a modem.

i might add however, sometimes you will have issues with the cable modem not wanting to renew fast enough.

like for example, if i go upstairs, and unplug my router, and put another router in it's place, then i will lose access, because the cable modem still is reserving the lease for the router it just saw.

so at that point, i have to wait for the lease to expire, which i beleive means, i wait 6 hours with the cable modem off. (at least i know this much, 2 hours wasn't enough, and 6 was.)

so if the router has given out three ip addresses during the course of you working on the network, it might be a lease expiry issue. *(at which point, even a working setup is going to seem to not work)*

during business hours, you can call your internet company, and ask them to renew your modem's lease from their end.

it's too bad the modems don't have a webpanel to admin them with, like routers do.:sad:


----------



## JustinTD (Dec 4, 2005)

Well you are correct, you would need two-three coax lines to get diff IPs. now the problem with the internal DHCP is its still a 192.168.xxx.xxx address which doesnt show up outside the modem. My external address is 68.xxx.xxx.xxx, and thats is what i would need more of, what i am doing is having a buddy help out by letting me drop the second server at his house.


----------

