OT - Need networking expertise please

[Matt.Hepworth]

I'm a networking hack. I can setup a server and run a few clients, but nothing too technical. Here's the situation:

 

Just got broadband today - was supposed to be a router, but they set up a modem. We have to get by through the weekend with it as it is. Running a Windows 2000 Server server and 4 other Windows 2000 machines on the network in DHCP.

 

ISP is a DHCP account - no static IP.

 

Modem goes to switch --> switch connects all computers.

 

I must make all computers access the internet and still be able to have full networking function (running apps remotely from server on all 4 machines). What do I do? Is there a device that could be a go between and provide a static IP so that I could simply setup dual IP's on each workstation? Can everything work simply with DHCP (the modem seemed to have taken over earlier and I couldn't access the server remotely)? Please help.

[Dylan]

Is your 2000 server setup as a true domain controller running DHCP, DNS, etc?

[phaeton]

slap a cheap-ass linksys 1-port router between the modem and the switch.

 

Tell the WAN side (the side facing the modem) to get its IP assigned by DHCP. Tell the LAN side (facing your computers) that you will assign them statically.

 

This way you can assign your computers off a scheme like 10.0.0.2, 10.0.0.3, etc or 192.168.1.2, 192.168.1.3...

 

--[cablemodem]--[router]---[switch]--[computers]

[Matt.Hepworth]

Yes, I'm quite sure.

[Matt.Hepworth]

I called my local computer store today and they said that there was NOTHING that could do that! I specifically asked about a router and they said that it wouldn't. I thought that was asinine that there would not be something that would!

[Matt.Hepworth]

Okay, since my modem was supposed to also be a router, will that solve my problem after the weekend? Would I still need an additional router? One more question, will I want to make my whole network static for this?

[Dak Lander]

Well, I'm not a networking pro by any means but your guys told you wrong.

Also, your modem is not a router unless it came with multiple outlets.

So, from your modem you'll need to run into a router. From there, to the computers.

Now, my Dlink will use, apparently, DHCP to acquire the dynamic or static IP, depending on your broadband criteria. From there you can set up static IPs for the rest of the computers on the network, with the router as a default particular IP address.

Really should't be that much of a big deal, once you have the router. Shoot, if nothing else, run a switch between the router and the computers but that adds extra connections and trouble.

 

As an amature home network hack, I don't think I'm too far off.

[Matt.Hepworth]

Originally posted by daklander:

Also, your modem is not a router unless it came with multiple outlets.

Yeah, it was supposed to be a router, but they used a modem and won't be replacing until the first of the week.

Shoot, if nothing else, run a switch between the router and the computers but that adds extra connections and trouble.

That's what I'll be doing since I already have a switch involved.

 

Thanks everyone! Looks like a router should solve my woes then. What about my previous static IP network qustion?

[Bill Heins]

Well here's our setup, four machines (Windows XP Pro, Windows XP Home, Windows 2000, and Fedora Linux) all sharing a broadband connection through a 4 port D-Link router. Each machine is given a different local IP address...192.168.yadda.yadda but share the external address. This is fine for file sharing between machines and sharing the internet, but for the server we use http://www.no-ip.com/ as the connection is dynamic...though it changes very rarely the external IP does change, using No-IP as a redirect it will always follow your current external IP.

 

For security reasons I would suggest not sharing drives but instead sharing folders on the drives instead

 

Darkon the Incandescent

[videoeditor1]

1. The modem that your isp gave you IS a router.

 

A router is a piece of hardware or software that determines where information goes. A router also acts as a gateway and joins two dissimilar networks.

 

Specifically, what you need is a router with NAT - network address translation (almost ANY Linksys / Netgear / Buffalo router). On the WAN side of the box you'll get, it will take that single IP address assigned from the modem.

 

On your LAN (local network), you'll have a bunch of fixed IP addresses to assign to your respective machines.

 

As an added bonus, most, if not virtually all of the home router boxes also include a DHCP server, you can specify the IP address range; and most include a firewall + scads of other cool utilities.

 

NYC Drew

[Matt.Hepworth]

Thanks Drew. BTW, I haven't heard the word 'scads' for years - thanks!

[Dak Lander]

Well, I told you I wasn't a expert but I still don't consider a modem that only connects to a single device a router. It may be adapting one type of network, the actual internet, to another network, your local network, but it doesn't route anything.

That's an adapter.

 

Again, I don't know anything about networks. I only have my small home network working, regardless what the professional technical nomenclature is.

[jlampson]

Matt,

 

Can you tell us details such as what ISP, what device they gave you, and so on? The device they gave you may have routing capabilities, regardless of number of network ports. The switch connects all the computers for you, but let's see if we can get this one resolved.

 

John

[Matt.Hepworth]

John, it's Comcast (small business services). The modem has no routing capabilites - it's a Motorola SB5120. I'm just going to buy a router in the morning and take it back if I can get everything running correctly when I have my router/modem replacement the first of next week. I'm still a bit shaky as far as whether I'll need to set everything up statically.

[Steve Force]

Cable Modems are NOT routers. They only provide connectivity--not routing nor subnettng functionality.

 

Good solution (which I use) is a Linksys wireless router, which provides:

1. firewall protection,

2, DHCP issuance of a SMALL number of IP addresses for the subnet,

3. the ability to specify which MAC addresses are allowed to obtain an IP address via DHCP,

others.

 

Cheap and very effective solution--saves me fro pulling wires, too.

 

HTH

[Steve Force]

Cable Modems are NOT routers. They only provide connectivity--not routing nor subnettng functionality.

 

Good solution (which I use) is a Linksys wireless router, which provides:

1. firewall protection,

2, DHCP issuance of a SMALL number of IP addresses for the subnet,

3. the ability to specify which MAC addresses are allowed to obtain an IP address via DHCP,

others.

 

Cheap and very effective solution--saves me from pulling wires, too.

 

HTH

[seclusion]

That's 2 thumbs up for the linksys... Did a 802.11G a couple weeks ago... You need to use your ISP modem for internet... They usually send you that when you sign up.. Them a router for sharing that internet access to up to 5-6 computers.. So what happens is the router connects to the modem gets it's Ip address from your ISP.. It stays connected all the time... The router will then assign IP's to your personal network.. DHCP, DNS etc is all handled by the linksys... You could static assign Ip addresses but why, what a hacker see's is your router only... They can hack that all you want won't get anywhere... PS. I just finished setting up one of my systems as a internet server... Kinda cool, cause my 2 studio systems are now connected together.. Now I connect the second computer using the first computers internet connection... 802.11G gives 56mbs... Works great.. But really I don't think ISP's send out routers... Reliable and really simple to use.... If you have a lot of Xp systems you may want to update just one to SP2 and use it's firewall, virus protection etc.... Otherwise you'll have to fiddle with all of them... Though the router has it's own firewall to..

[Super 8]

Is it just me, or do they make this stuff needlessly difficult?

 

Here's what I did to make two computers access the Internet.

 

I used a patchbay to network the computers.

 

I set one computer up for Internet connection with the cable modem via USB.

 

I used Windows Home Networking and set it up to Share it's internet connection.

 

It worked just fine.

[Steve Force]

Yes, but your firewall is, how can I put it...practically nonexistant? Nothing against the Microsoft firewall solution (I am sure others will speak up here...) but you are potentially exposed to several Internet issues..

[deanmass]

The computer store people are idiots. Do not ever call them again. If that is what they actaully said, they are either stupid, or were blowing you off.

 

Do what Phaeton said.

 

Go buy a Linksys or netgear router. Since they are so cheap, just get the one with built in wireless.

 

It will usually have 4 local network ports, 1 WAN port.

 

Connect the WAN port to the cable modem.

 

Connect your home machines and server to the LAN ports.

 

There will be instructions with the router on how to setup the stuff 'internally, but basically, here it is;

 

Your router will get the 'dhcp' address provided by the ISP.

 

Your router will supply the PC's connected to the LAN ports with it's own automated IP numbering scheme, usually 192.168.1.x, with x being a varibale based on the number of attached machines. You usually have the option in the router settings to say 'Only hand out 5 ip addresses on the LAN ports, and start them at 100, thus giving you the ip addresses x.x.x.100, x.x.x.101, x.x.x.102,x.x.x.103, etc.

 

The router takes all these internal port connections and pumps them through the WAN port with the 'dhcp' ip address provided by your ISP.

 

A decent little router with wirelss should cost no more than $100 now, and if I am not mistaken, COMPUSA was advertising a Linksys 4 port with wireless for $39.99 last weekend. The wireless will just be nice to have in case in the fture you get a wireless laptop, have a friend over with wireless, etc.

[jlampson]

Originally posted by forceman:

Cable Modems are NOT routers. They only provide connectivity--not routing nor subnettng functionality.

I wasn't sure which post to respond to ( ), but some cable providers do provide devices with built-in routing functions. These are usually reserved for business customers, but a few get snuck onto the residential market. As long as the Internet works on one computer, that's enough for a lot of people. Until recently, not too many households had two computers, much less one, in my experience. Amazing.

 

John

[bassix]

A cable modem interfaces between your ISP's network and your network interface card. This NIC gets its IP address from your ISP's DHCP server.

 

What you want to stick in between the cable modem and your NIC is indeed a cable router (like the linksys befsr41).

 

The WAN side of this router acts as if it were your NIC and so gets its outside IP address from your ISP's DHCP server.

 

This Router uses NAT (Network Address Translation) to interface between the internet and your local network.

 

By default the inside IP address for these routers is 192.168.1.1. It also runs a DHCP server on the inside network range by default (probably with a scope from 192.168.1.100 to 192.168.1.150).

 

Connecting any Windows box directly to the internet is a bad idea (virii, worms, hackers etc. coming in).

 

The router keeps all ports shut on the internet side and thus keeps most worms and hackers out. You can forward some ports (ftp, telnet, smtp etc.) to the IP address of your server if you need to.

 

Seems to me this is the device you need. They're very easy to setup as well.

[Matt.Hepworth]

Originally posted by jlampson:

...some cable providers do provide devices with built-in routing functions. These are usually reserved for business customers...

John

Yes, I'm a business customer in a comercial building. I raised a stink with them and they will have my router to me to replace the modem by the end of the day. Hopefully, I won't need a separate router, but if I do all the advice given has been invaluable.

 

Thanks everyone.

[videoeditor1]

Originally posted by forceman:

[QB]Cable Modems are NOT routers. They only provide connectivity--not routing nor subnettng functionality.

1. Maybe you should start by defining what a "router" is. Then I can give you a few examples of cable companies (in NY and across the country) that provide a modem that also provides a routing function. Virtually all cable modems are actually "gateways". Virtually all DSL modems are gateways AND routers.

 

2. Answer this: If cable modems do not provide routing and/or subnetting, how is it that if your machine is connected directly to your cable modem, you are GENERALLY unable to see the other cable modems in your (assumed) network?

 

Just curious.

 

NYC Drew

[Steve Force]

(Long post..)

 

Routers span different networks. Cable modem is just that: a "modulator/demodulator", which changes, for example, digital to analog (example being a computer modem hooking a computer to a phone line: the phone line is analog, the computer is digital.)

 

The cable modem is the end-point for the network (Internet) in this case, and is not network addressable.

 

If I only had one computer that I wanted to have access to the 'net, I could simply plug the Ethernet cable from the computer into the cable modem.

 

Then, to get access to the Internet,my computer would request from Comcast an IP address.

 

For example, my IP address is currently 68.41.xxx.136 (third octet, (class c) the xxx, changed to protect my network from hackers.)

 

This IP address is "leased" to me from Comcast for a finite period, say 3 days. At the end of those three days (actually earlier) my computer requests an IP "renewal" and the Comcast IP address issuer, the DHCP server, grants it.

 

Since I want multiple computers accessing the net, and have only one IP address available to me, I need to use a technique which allows several computers to use (share) one IP address. This technique is called network address translation (or NAT). I get this NAT functionality by using a NAT-capable router (which, again, spans different networks-in this cast, the Internet is one network, my home network (my computers) are on another.

 

The device I use, the router, is a Linksys Wireless router. As described in other posts, Wireless provides Ethernet connectivity via radio frequency, rather than via a cable. Anyway, the Linksys router now is the dude which requests the IP address from the Comcast DHCP, server rather than a computer.

 

Make sense so far?

 

Well, then for my home network (subnetwork), the Linksys router provides the same functionality the Comcast DHCP server does, only it provides IP addresses for my subnet. The Internet has NO IDEA I am running multiple computers, nor does it care.

 

The Linksys router also acts as a firewall, which only allows certain directed data through it (to complicated to describe ports here), which strongly protects the computers this side of the firewall.

 

I hope that this adds some value to this fine forum.

 

Regards!

 

EDIT: I see where bassix added some value to this thread prior to my post. Read both of our responses and you should have a pretty damn good idea of how the 'net, cable modems, routers, firewalls, et al work.

[Matt.Hepworth]

The bastards brought me a gateway to 'get by' until Monday/Tuesday when the business networking router is back in stock - I'm worse off now than I was when I had the modem. At least with the modem I was temprarily running by assigning my server a static IP in the range that the comcast DHCP was running 67.171.xxx.xxx. With the gateway, it only assigns a 4 IP range. I can't get anything to work that way.

 

If I set everything including the server to DHCP could it work?

 

Also, could someone summarize in the tc/ip properties box what 'default gateway' and 'dns server' do. Using static IP's, my server will always have the 127.xxx.xxx.x gateway assigned.

[deanmass]

OK...

 

Nearly any computer or computer device can be a router. A router routes.....It 'connects' logical devices to their physical places

 

A DNS server does nothing more than tell your computer that www.eqmag.com=x.x.x.x ip address. If DNS is down, you will not be able to type in a 'www' based address. If you know a web servers' IP address, you can still connect to it without DNS IF you type it's address in to the browser address window. Use one of mine to test 204.39.0.153

 

NowNE, here is the breakdown..

 

Cable modem provides your computer/network with a connection to the comcast network. The cable modem is also capable of holding the 67.171.xxx.xxx IP address.

 

Router (which will have 2 ip addresses, the 67.171.xxx.xxx that the cable modem provides it, and the internal address that allows your other network devices to 'see' it.

Ethernet out from cable modem to WAN port on the router.

Port 1 on Router, plug in to the server ethernet port

Your home server

Set it to the following

DHCP for the IP address

DHCP will provide; an ip address, the gateway ip address (which is the IP address of the router) and the router will connect you to the DNS server from comcast.

 

The 127.x.x.x address you refer to is the default 'self imposed' ip address for what is called a ;local host', so, if you were to install a web server on this PC, and wanted to browse the web pages stored on it, you coudl type 127.x.x.x. in the browser window.

 

So basically, the comcast cable modem gives 1 ip address to the router.

 

The Router hands out more ip addresses to your network, and routes the traffic from all these 'internal/home' ports to/thru the 1 IP address that Comcast allows you to have. Think of it ( a very simple analogy) as a cable splitter. The router can do more, but basically, it's job is to allow a bunch of stuff to connect to one connection, and send the correct data back to the correct place. The router uses DHCP to give each device a unique number, so it knows what goes where.

 

Depending on the brand of router you buy, it will have it's own preset ip address for the internal network of 192.168.1.1, or 192.168.0.1. The subsequent pc's will usually be numbered upwards from there, i.e. 192.168.1.2, 192.168.1.3, etc. Everything with a 192.x.x.x address gets pumped through the 67.171.xxx.xxx comcast address by the router.

 

Hopefully this makes sense.

[Matt.Hepworth]

Originally posted by deanmass:

A DNS server does nothing more than tell your computer that www.eqmag.com=x.x.x.x ip address. If DNS is down, you will not be able to type in a 'www' based address.

I realized the answer as soon as I edited my previous post, but didn't take the time to edit that part out.

 

Port 1 on Router, plug in to the server ethernet port

All computers are connected to a switch (I won't be eliminating it yet) - this should still work, correct?

Your home server

Set it to the following

DHCP for the IP address

DHCP will provide; an ip address, the gateway ip address (which is the IP address of the router) and the router will connect you to the DNS server from comcast.

So, set my company's main server to DHCP and everything will be assigned by the router? That can't work because it's too easy!

 

The 127.x.x.x address you refer to is the default 'self imposed' ip address for what is called a ;local host', so, if you were to install a web server on this PC, and wanted to browse the web pages stored on it, you coudl type 127.x.x.x. in the browser window... Hopefully this makes sense.

Yes, I follow.

[deanmass]

"All computers are connected to a switch (I won't be eliminating it yet) - this should still work, correct?"

 

Kind of. If your switch has an 'uplink' or MDIX port, you are good to go, just plug into one of the router ports. If not, you need to make or buy a crossover cable., assuming the router does not have an uplink port other than the wan port. All the crossover does is switch one pair of the 4 pairs in an ethernet cable. No big deal.

 

If you have established drive amappings based on IP addresses, you will have to re-link them, but if you are running WINS or a host file based system, it should be transparent.

[Matt.Hepworth]

Shouldn't the switch eliminate the need for a crossover cable? I thought that's what switches do vs hubs. I have no problem making a crossover cable, if necessary, I just don't see that it will matter as a switch does not care whether it sees a crossover, or standard cable.