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Networking help: 2 IP addresses?

ehbowen

Banned
ehbowen
Joined
Nov 23, 2002
Messages
281
Location
Houston
All right, I'm trying to coordinate installation of a new network-based building lighting controller at my work site. The components are 2 Windows XP computers, 1 in the control room and one in the security office about 200 yards away, and the controller itself which will also be located in the control room. Each machine needs to have a static IP address, either internet or LAN (192.168.X.X).

The problem is that our building's data network contractor charges $150.00 per month per machine to hook into their network, and management isn't happy about paying an extra $500 per month from here to eternity. The alternative is for us to run our own network cable (plus probably a couple of repeater switches) and set it up purely as a LAN. Management is leaning that way, partly because they're not too thrilled about giving unfiltered internet access to all of the night shift security guards. The downside is that without internet access, it becomes difficult or impossible to download updates and security patches.

Don't broadcast it to our network contractor, but one of the IP addresses we're already paying the $150 a month for is actually a Linksys wireless router which allows us to go online with laptops and the like, and that is how I updated our existing control computer to Service Pack 2 for the new software. That computer does have 2 network adapters, one on the motherboard and one expansion card, so the hardware for what I'd like to do may already be in place. My question is, how do I configure the computer so that I can connect one adapter to the LAN with fixed IP addresses for the lighting controller and software, while retaining the option to hook the other adapter up to the Linksys box (which doesn't provide fixed IPs) for software and security updates? Bonus points if you can tell me how to share the Internet access from the Linksys box with the other machines on the LAN.

Sorry if this is an obvious question, but aside from hooking my own home computers up to DSL I have no experience in networking. I will be grateful for any help anyone can offer.
 
hi, you'll be glad to know that IP addresses are bound to the network cards. Go to "control panel" -> "network connections". I'm happy to help but I'd suggest that you start with the network wizard that comes with XP.
 
I'm a little confused.

From what I understand, you already have a linksys box which basically allows you to run your own LAN through a $150 connection. Why can't you plug in this machine there? Do they have a way to monitor who connects to that linksys box and charge you per connection depending on MAC addresses?


If you are trying to go for a LAN inside the LAN (The computer with 2 NICs will basically end up as a router), then simply get another Linksys box and connect it to the one that already exists, pretending it is the 150 dollar connection. This way you will have another LAN within your original one that will show as 1 machine.
 
Your linksys hub has three components:
An IP address server (A DHCP server)
A NAT firewall
A simple switch

Each network card needs it's own IP number and it can get it in one of two ways.

1: You can manually assign a static IP number. This is the hard way, but sometimes needed. A static IP is fixed and never changes.
You also need to set two other numbers manually.
One number is the subnet mask. The mask is the same for all your PC's and the hub, something like 255.255.255.0 The second number you need to set is the IP of the 'gateway'. This is the linksys hub. Probably 192.168.1.1

2: Get the IP via the DHCP server. This is the default. For your linksys, it will assign IP numbers from 192.168.1.100 to 254 The gateway and subnet mask are also delivered automatically. The downside of this is that a PC IP address can occasionally change.

Your hub will allow static numbers to be assigned from 192.168.1.2 to 99
It is up to you to keep track of what is assigned, and if you assign two PC's with the same number you will have some troubleshooting to do.

You can put two network cards in a PC easy enough, and assign one card to DHCP and the other to static.

Your contractor should not be bothered by what you are doing. You are not stealing any bandwidth because all the PC's are going to use the bandwidth of the single port on the linksys router (labled 'internet').

If you have a new enough linksys router, you can block certain PC's from accessing the internet at different times of the day. If you have an older router (older than a year or so), update the firmware or just buy a new one, they are only about $60.
 
Your control devices might want their own IP's though, separate from the 192.168 network. Just make them whatever you want. 192.169 or something like that.

200 yards will present some issues.
 
I get the part about hooking the computers to the Linksys box; I do that frequently and it's quite transparent. The issue is with the new lighting controller; it expects everything to be on fixed IP addresses (and it needs one too). If I go into the Linksys router to make everything fixed, though, it will probably adversely affect the laptops on the wireless network which come and go during the day (which is why we have the wireless router in the first place).

So the first priority is to set up a LAN for the lighting controller and its front-end computers with all fixed addresses. Secondary objective is to make it possible to either permanently or occasionally hook up at least the control room computer to the Linksys router for Internet access without disrupting the router's use for our laptops. Finally, if possible, I'd like to set this up so that when the control room computer is connected to the Internet through the Linksys router it can share that access with Security's computer over the fixed-IP LAN. How much of this can be done?

Finally, as far as our 200 yard distance is concerned, what are our best options? Management is willing to consider running fiber optic cable if necessary, but could we get away with Cat 5 with switches every 50 yards or so? (The cabling, whether Cat 5 or fiber, will run through a dedicated and existing tunnel through the basement for most of its length.)

A reference to a good web site with basic networking info might be appropriate....but thanks to everyone who has tried to help so far.
 
ehbowen said:
Finally, as far as our 200 yard distance is concerned, what are our best options? Management is willing to consider running fiber optic cable if necessary, but could we get away with Cat 5 with switches every 50 yards or so? (The cabling, whether Cat 5 or fiber, will run through a dedicated and existing tunnel through the basement for most of its length.)
Click to expand...

If management is willing to run fiber then run fiber. It's going to save you a lot of problems in the long run.

Cat 5 (or 5e which may help with any crosstalk) cabling with repeaters will work, but you're introducing several points of failure. If you can get management to pay for the stuff that works, go with what works.

If I understand your problem correctly you may want to look at a free product called ipcop (http://www.ipcop.com). You can put 2 network cards in the system; on "RED" and the other "GREEN". The RED connection would go to your internet connection and the GREEN would go to your LAN.

You can set up DHCP via the IPCop web administration interface for the GREEN side. The RED side you could connect to your linksys router. The layout would look something like this:

Internet---->Linksys------>Ipcop RED----->Ipcop GREEN----->Your network

IP's........... 192.168.1.1.....192.168.1.2.......192.168.159.1.......192.168.159.2-254


IPcop also has a proxy you can use along with network shaping and a few other neat toys. It's easy to get up & running with the basics and you can add stuff as you get more familiar with it.

You could also accomplish a similar scenario with a second Linksys router, though the traffic shaping and proxy configurations wouldn't be available. But it would give you a single IP address that other systems can use.

I may be misreading what you want to accomplish here so take the above with a grain of salt.
 
http://compnetworking.about.com/od/tcpip/TCPIP_Transmission_Control_Protocol_Internet_Protocol.htm

The linksys router is capable of supporting both leased and static addresses. The one linksys router should be able to suffice for the entire network.

You do not need to have the entire network static mapped, just the controllers.

All right, I'm trying to coordinate installation of a new network-based building lighting controller at my work site. The components are 2 Windows XP computers, 1 in the control room and one in the security office about 200 yards away, and the controller itself which will also be located in the control room. Each machine needs to have a static IP address, either internet or LAN (192.168.X.X).
Click to expand...
I read this:
3 devices:
Device 1: XP PC in Security office '200 yards away' needs a static address
Device 2: XP PC in controller room which needs a static address (nearby)
Device 3: Non PC controller which needs a static address. (nearby)
Device 4 thru x: other PC's that do not need static addresses (nearby)
 
From what I can tell you simply want a static range of IPs to assign manually.

I have this setup at home:

Set up your DHCP server in the linksys box to start handing out addresses beginning at 100. That leaves the static addresses 2-99, free for you to use on any device that requires a static IP.

It has been a while since I messed with networking but I do remember that there is a limit to how many repeaters you can put on a wire.
 
The maximum length of a UTP network segment is 100 meters. The maximum distance between any 2 devices in the same collision domain is 200 meters. 10 BT (10 mb/s) networks can have up to 5 repeaters (hubs) in any path. 100 BT (100 mb/s) networks can have up to 3 repeaters in any path. A network switch isolates the collision domain and can extend the network indefinitely. Gigabit (1000 BT) cannot use hubs so all connections are point to point and the maximum cable length is 100 meters.
 
I'm just shocked that the network contractor gets away with charging $150/month just for a network connection.

That's highway robbery in my opinion.
 
What is the standard rate for commercial internet connections in that area? They also would be providing the building network infrastructure monitoring and perhaps some tech support. But mostly they probably have a captive audience.
 
It is very much a captive audience. They have an exclusive contract with the city for all network, data and phone service to all customers in the building--except for the city. The city has their own IT department, but so far I've heard nothing encouraging back from the city about hooking into that network. If we did it, it would require about 150 yards of cabling from the city's offices to the security office, plus the 200 yards from the security office to the engineering control room. (The building takes up 7-1/2 city blocks, and the city offices are in the extreme southwest quadrant while we are somewhat north of the centerline on the extreme east side.)

I'm going to try to talk them into running a fiber optic connection, preferably to the city's network. If they won't let us, I'll at least try to get fiber on this lighting system LAN. If I do have to hook up to the Linksys box for net access, how do I set it up? I dug into my own home network box and I can see spaces for entering static DNS's, but reading the help screens it seems as though those entries are for outgoing (internet) DNS's and not for the incoming LAN. If I just manually key in a made-up IP like 192.168.1.20 on the lighting computer along with the proper subnet mask and a gateway of 192.168.1.1 for the Linksys box, will the network operate as it should? Or does the router have to be programmed with the static IP as well? I might just try it out and see what happens.
 
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The DHCP is a pool of IP numbers you can draw from, like from a well. The DHCP gives out more than just the IP, it also gives the subnet mask, gateway, and DNS.

A static IP number is manually assigned as if you had a bunch of vacant houses with no addresses. As you assign each house a mailbox, you write a number on it.

The DHCP pool on your linksys starts at 192.168.1.100 (unless you changed it). The hub does not do anything to give static addresses, but they can be assigned from 192.168.1.2 to 192.168.1.99 .

Yes, you could make a network entirely of static addresses but this is hard to manage. Each time a new laptop joined your network it would need to be given an address, mask, gateway, and dns value.
 
I am still not sure we are all thinking of the same configuration. I drew a quick diagram of what it sounds like to me.
106146174c3255448.gif


This may be slightly more complicated than you need, because if you can assign your own static numbers to the light controllers you would not need the second switch and network cards, just your linksys hub.
 
This layout seems more simple, but it will only work IF you are able to control the static IP numbers on the controllers. The controllers will probably need to know where each other is addressed. You may find that you are not free to change their IP addresses to whatever you want.

10614617525168ee4.gif
 
This is a good time to make sure we are all thinking of the same configuration and limits. :D
 
Kopji--

Your second drawing is closer to the configuration. I don't have any drawing software handy, but here is a text description:

Linksys router: Connected to internet via building network.
Laptops: connected to router via wireless, they come and go (need DHCP).
16 port switch: Hardwired to Linksys router (100 ft. Cat 5e).
Control room PC: Directly connected to 16 port switch. Needs static IP.
Security office PC: Will be connected to 16 port switch via 200 yard fiber optic run (probably) or Cat 5e (with at least 2 intermediate repeater switches). Needs static IP.
Lighting controller: Directly connected to 16 port switch. Needs static IP preprogrammed at factory (well, by installation technician), expects front-end control computers to have static IPs as well. Communicates with individual lighting relay panel controllers over proprietary 2-wire twisted-pair network (already in place and not part of my problem--don't worry about it).

It's beginning to sound as if the problem may be simpler than I first feared. I was thinking the router had to be programmed for the static IPs, but it sounds as if I just assign them, as long as I don't get confused and use the same one twice, the router will recognize it.

Now, to find the password for the router--the guy who uses it most often says he's forgotten it....
 
Passwords are no problem. All I need is to find a post you made from the office... maybe on another board... Ah, here we go.. backtrack the IP address to the router.. run the crack script.. (this may take a few minutes) ..

Here it is (please don't anybody else look, this is private)
The password is: "admin".
 
The difference between drawing #1 and #2 is that for #2 the controller people are able to set the static addresses to whatever you want.

There is a company called 'BlackBox' that makes a variety of signal boosters and converters that might help with the 200 yard run. Fiber is good but sometimes hard to work with and expensive.

If you have not set static numbers before, there is a an XP utility you can run from the command prompt that is your friend. It is

ipconfig /all

Will show you everything about the network card values.

Good luck and hope we have been of some help.
 
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