Help with LAN setup

[Strych9]

I am currently running a 4 computer LAN sharing a cable connection with a Linksys Cable/DSL Router. Under my current setup I only have one external IP number. The router has DHCP enabled to assign internal numbers to the four machines for the LAN side. All machines are using Win98.

My cable company now offers up to two additional IP numbers for a small additional cost. I was thinking about getting these two additional numbers to try and eliminate some of the problems I have had in the past accessing the same servers (mostly game) with more than one computer at a time.

The problem is I am unsure just how to configure the LAN with the additional IP numbers. In the past all machines went throught the router and I just enabled DHCP which took care of assigning internal numbers allowing for internate sharing with only one external IP visible to the outside world. With the additional IP's I will have 3 machines with unique external IP numbers and one without that must share??? I have lots of questions regarding how to set this up.

Will the machines with unique IP numbers not be going through the router? Do I need additional hardware such as a switch? I guess I still need DHCP for the computer without a unique IP number. How does this work when only one machine needs to share an IP number and the rest don't. Will I lose the protection of the router firewall? I would apprecitate it if someone could explain exactly how this needs to be setup.

Thanks for your help.

 

[Strych9]

^

 

[tippmann]

This may take a few trys, but we'll try an give you some answers...

1.Question, are you using the Linksys router with 4 ports? (I am guessing that you are due to the fact that you have 3 compters)

2. The computer with a unique IP with be going through the router, but not through the firewall/DHCP. You will lose the security... Not Good..

3. Here are some ways to game with out the exta IP number


Info from Linksys page

Games over the Router. If playing games like Quake or Battle.net, port 27960 must be opened in the router's advanced feature. Refer to the manual and the help button on the router on how to open ports.
==================
DMZ Host
The DMZ Host setting allows one local user to be exposed to the Internet to use a special-purpose service such as Internet gaming or Video-conferencing. To expose one computer, enter the computer?s IP address and click the Apply button. Inactivate DMZ by entering a zero (0).

http://www.linksys.com/support/support.asp?spid=1#adv

 

[Strych9]

Yes, I'm using the Linksys 4-port router. The problem with sharing one IP is that there are a lot of servers out there that won't allow two instances of the same IP# to log in at the same time. It really has nothing to do with the setup at my end. Regardless of what I do to my setup you need different IP#s to get logged in. It is how they are configured and what they allow. I'm also trying to decide if I want to dedicate one of my machines to a game server.

I'm still just exploring whether or not I want to add the IP's. Lets assume I do add them so I would have a total of 3 IP's for 4 (and possibly more) computers. Can someone give me an idea of the physical layout/setup involved in addition to what I already have? Thanks.

 

[Strych9]

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[Strych9]

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[Strych9]

Anyone at all???

 

[bex0rs]

Well, if you are going to have > 1 "public" IP (from your ISP, of course), you will need purchase a hub or a switch. (I'll be referring to this as a switch from now on.) The idea is that you will be plugging the network cable that normally goes modem -> router instead to modem -> switch. From there, you will be able to set up 2 of your computers directly on the switch with "public" IP's, which would probably be assigned by your ISP if you are using DHCP. Then you will also connect the "WAN" port on the router directly to the switch, and this will use your third available "public" IP. Your other two clients will each plug into one of the four ports on the router's built-in switch and they will have "private" IP's. So basically you are going to have two seperated networks, one directly on the internet, and one behind a firewall. I could draw a picture and send it to you if want. I'd prefer not to risk ascii art.

You're probably going to have more questions because I just covered the hardware setup, so feel free to ask.

~bex0rs

 

[Strych9]

Thanks, thats actually the way I thought I would have to set it up. I actually made a drawing exactly like that already. I'll try and get it posted so you can let me know if I have it right.

 

[bex0rs]

.

 

[Strych9]

Here is the diagram I made. Are there any other options?

 

[Russ]

Drawing looks just fine. Similar to my setup, except I'm on DSL, and have a couple dozen systems plugged in.

Russ, NCNE

 

[Strych9]

Thanks guys. Are there any drawbacks to this setup as opposed to my current setup of having all machines going through the router. I guess I will lose the firewall for two of the machines.

 

[mofo888]

drawing looks good.
i guess you will need to install software base "firewall" to protect the other 2 computers (not behind the router)

 

[Strych9]

I already use Zone Alarm. That should be good enough right? Are there any other setup options that I should explore? I like having all my machines behind the router but I guess I won't be able to keep it that way if I want to use multiple IP's.

 

[Strych9]

Any other options here guys?

 

[bex0rs]

What other options are you referring to?

~bex0rs

 

[Scarpozzi]

I'm lazy so I didn't read all the comments of other people...just your main question. From your External DSL or Cable Modem, you'll have to have at least 3 open ports on a switch for the 3 total IP addresses....then you can hook individual routers up to each port or just use one router and put your computers on the open ports, unprotected from firmware. The point is that you are going to have to use the cascading effect that networking tends to create.

-----ROUTER or Computer
/
MODEM---SWITCH -----ROUTER or Computer
\
-----ROUTER or Computer
Then you can cascade down from the routers to switches and what not to create even more segments of your network. The only drawback of having too many routers and switches is that your limited bandwidth will only support about 8-10 computers. So don't get greedy like I am... I hope that answers your questions...

 

[Scarpozzi]

Ohh yeah, one more thing...most ISPs use either bridged circuits or some sort of password authentication (such as PPPoE) to register the computers they DHCP to. So when you plug the computers in on your network, they will have to login somehow...either with an adapter address or some sort of software password...your router already has that option built in... So if you need to purchase additional routers, the linksys isn't a bad choice.

 

[Strych9]

What would be the advantage of having multiple routers as opposed to the setup I have posted here???

 

[Russ]

Strych9,

Your setup is fine.

Russ, NCNE

 

[bex0rs]

Well, having three routers plugged into your switch, then having each client plugged into its own router would solve your problem of wanting each client to appear to have it's own public IP, and it would provide a hardware firewall for each. Of course, this is going to cost you 3*(cost of one router) so be prepared to spend money. Then you could connect all of the routers via crossover cables so that the clients would be able to share files with each other via your "internal" network. That is just a suggestion and something that I would not do.

I personally use a FreeBSD box as my NAT firewall, and I've never had any problems with programs or servers needing their own unique public IP. I suggest that you research your programs a bit before committing to getting multiple public IP's and therefore segmenting your network unnecessarily.

~bex0rs