normal questions about networking

hello

i have been thinking about making a new network...

now i have two computers, each of them with two ethernet cards, one of the cards connects to the other computer, and the other card in each computer connects to a cable model (this means i have two cable modems) simple, right?

but if i buy a new computer i need to have a network with a router... so i was thinking about getting a wireless network, then i would also have to change my internet connectio, only one connection that connects to the router and shares it with all the computers.

im posting this message now because i saw a review of a wireless router, one from linksys and i was very impressed! the configuration lets you setup many things! for example security... it has a firewall, it even controls cookies, active-x, java, the router (hardware) huh!?

one of the things that makes me want to start a network is the new ability to connect usb or rj45 devices to the router, and that router will make the device being able to be used by all the computers, for example:

network harddrives by ximeta http://www.ximeta.com/

thats great! and it used rj45! well... the truth is that even four 250 gigabytes harddrives are not enough for me hehe, and i don't think that a wireless router has so many rk45 ports! say, could i connect a normal ethernet hub to the router and then connect the harddrives to that hub, will it work!?

some routers also have usb connections, right? they let me share printers, i never used a printer so maybe someone else could talk about this... would be nice. http://www.hardware-pacers.com/pages...=280&catType=r

now the questions...

the internet... with three or more computers connecting to the internet using the same router, theu ip address's in the internet will be the ip address of the router, right? this means, i will have three or more computers with the same ip address, that could be a problem, for example:

hosting game servers, what if i want to host three servers... each in one computer, the ip is the same, the players will connect to what computer?

limits... for example so internet relay chat networks have ip address limits, no more than two connections per ip address

i have heard about "port forwarding" but i really don't know what it is...

what about "dmz, demilitarized zone" what is it? what i read is that it reveals your computer to the internet...

the biggest problem for me will be compatibility with linux, slackware, is it safe?

well, i can't remember of anything else now... i think that i will have questions about how to setup the hardware.

i should wait some time until i buy a good wireless network, now that microsoft will change the wireless setup with the microsoft windows xp service pack 2... maybe things will change i don't know, what do you recommend? any new technology coming out?

thanks!

wow....you have a lot of questions in there....
One thing that jumps out at me as requiring a response is your question about all the computers having the same IP address.
The way that works is you have your public IP address that belongs to your router, all the other computers on your network will have public IP's assigned to them (ie 10.10.0.0 or 192.168.20.10).
I don't have any experience with wireless networks, so I'll leave that portion of your post for somebody more knowledgable then myself to answer for you.

I recently bought a wireless router with a built in dsl modem for my house,

I have my laptop with a wireless pcmcia card in it which obviously connects to the router and my desktop is hardwired in to the router, which in turn is connected to the built in modem.

The modem is what connects to my ISP and is assigned an IP address by my ISP, My laptop and desktop connect to my modem via the router and have the IP address I assigned to them 198.168.x.x .

If they go onto the internet obviuosly they will go through my modem, so as far an the internet is concerned my IP addy is the one my modem has (the one my ISP gave it)

However as far as my network is concerned the IP addy of the computers are the one i gave to them, it is not concerned with the one my ISP gave me.

It doesnt matter which computer goes on the internet or if all 3 of yours go online at the same time they will all use the IP addy your modem has.

This is cut and pasted from my router help file -

DMZ- If you have a client PC that cannot run an Internet application properly from behind the firewall, you can open the client up to unrestricted two-way Internet access. This may be necessary if the NAT feature is causing problems with an application such as a game or video conferencing application. Use this feature on a temporary basis. The computer in the DMZ is not protected from hacker attacks. To put a computer in the DMZ, enter the last digits of its LAN IP address in the Static IP field and click "Apply Changes" for the change to take effect.

I put my computer in here when i play things like virtual pool 3 on the net as it uses a different port every time the bloody thing connects to gamespy!


I cant help you on port fowarding as im not to sure on that myself!

I hope it helps a bit, i found it easier to just experiment with your network and learn thing as you go along, hell you can always reset your router!!

Okay I will answer your questions by telling you my setup. First off, I have a Linksys wired router (linksys makes a fine wireless router [ I would get the G]). It has 4 ports on it and into it I plug

1. Main Winxp/Mandrake linux box
2. Win2k node
3. Snort box (slack running snort as an IDS)
3. 8 port switch

Next, I set up the router to act as a DHCP server and I have all the computers on my network automatically pulling their ips from the router. They start at 192.168.1.100 and the router ip is 192.168.1.1

Next, I have all the files on my windows boxes shared so that the other boxes can read and sometimes write to them. As for my linux server (which is down the switch) it is running samba with 120 and 160 gig hardrives that are r/w with all the coms.

On my router, I have a few ports forwarded. first Ident (113) to a empty ip (192.168.1.254) because linksys closes this port by default if it isn't mapped anywhere. Next, I map incoming requests for my ntop server (3000) apache (80) and sometimes irc (a few ports) to the linux box (192.168.1.103). This is all configured through the router. Also, I have port triggering set up so that if an application that I commonly use needs to open a port, it does. For this I have an smtp server on the server, and irc ports on my main box (192.168.1.100).

And the rest:
As for DMZ, unless you are running a honey pot, don't use it...nuff said there.

Next, for IRC, I have had up to 4 clients running at once behind my router (mirc, 2x xchat, and Bitchx).

For game servers, just map the incoming port to whatever box is running the server. This can be done through your router.

Don't buy network hardrives, that is silly and overpriced. Just put them in your computer and share them on the network. I promise that everyone will be able to see them :D


If I missed anything, I am sorry, but I have to get a hair cut.

thanks for your time!

i think that i will have lots of problems with the security setup and firewall rules, i never heard of opening and clossing ports in a router, only in a computer. it will open and close ports for all the computers...

i still think that i will buy the netdisk's that way i won't need to have a computer turned on and i dont even need to setup network share, safer.

there should be a pci card with ethernet and bluetooth connections hehe, that why i wouldn't have to have two network cards in my computer, i always need a rj45 card for lanpartys, etc.

Well I guess I can give a little opinion on the game servers and port forwarding. I have a slackware box running SSH as a small private wargame on my network. From what I understand you want 3 game servers on essentially one public IP. Well in your router configuration it will have advanced options, then there should be a tab for port forwarding. What port forwarding does is send all information coming to a certain port to a internal IP address. So say your IP address is...10.10.10.10 and your internal network IP for the game server is 192.168.1.100. In the port forwarding tab you open the range of ports for that certain game server...and then select the internal network IP address you want it to be sent to. Then just do the same thing with the other game servers...the only thing you have to remember is that they all cannot be ran on the same ports, so all 3 game servers need to use different ports(which isn't a problem nowadays because most games let you select a wide range of ports to use).

Just a few comments on your possibilities here:

You're working with it looks like three different problems: network routing, introducing wireless, and handling server resources through a router. I'd recommend thinking of these as nested problems.

The network routing is the most basic layer in that it should be platform independent and capable of handling whatever traffic you throw its way -- if you get a decent router (wired or wireless) that provides network address translation most of your problems are handled there. Your router can even deal with some of the security concerns as you've mentioned (ActiveX, cookies, blocking incoming traffic in general.) So the first thing I'd figure out is what device to get in this regard. The concern I have is that you mentioned that you have two cable modems . . . and most routers a person would buy for personal use only have one incoming interface. Do you intend to use two incoming Internet connections? If so, this could be another kind of complicated.

As for the wireless possibilities, if you're going this route keep things as simple as possible. Buy the latest and greatest wireless router you can get and plan on using it for your entire network, and plan on buying wireless cards from the same manufacturer. This will help reduce configuration problems and increase your chances of setting up a secure network. Keep in mind, however, that if you go wireless you are limiting your speed on your LAN. You can get a gig-ethernet wireless LAN up and running pretty cheaply, but a wireless LAN will be throttled at about 50mbps (no matter what the box says). Go wireless with some caution. For all the ease of cabling you gain you limit yourself in terms of compatibility and performance.

Now I'm not going to go into the networking requirements for serving games or whatever on your LAN because there are a lot of other posters who will have good thoughts on that, but I will re-iterate that if you're going this route, a wired network will make life easier. And cheaper.

And I'll also voice my opinion that networked storage is a waste of money. Buy internal drives - they're cheaper and easier to maintain.

hmmm, but sharing harddrives is a security problem... i don'r even know how it works in a network with a router, do i still need a firewall?

so i will always need to network cards, one for the ethernet and one for wireless

If you're going to have this network on the Internet, you should have a firewall no matter what. The lucky thing is that a number of wired and wireless routers have firewall or firewall-like capabilities built in.

hum i dont think that network drivers are safer than internal shared drivers.
Due to some "restrictions" on their configurations, netdisk can have even weaker security against pc drivers. Please compare security options of your netdisks (that you want to buy) and regular shared disks (*nix, Windows)
Also please be aware that some ISP doesnt like that you act as a big server node and eat a lot of BW. Also There is some ISP that has specific clauses to disallow more than ONE computer connected on their links.
Ahn, you will say "they cant see, because im have a NAT firewall"
and i will reply "yes, they can". Like in your config, with mixed O.S. is a piece of cake to know there is more than one. Just some concerns

and will i still need a software firewall if i buy a router with a firewall? like for example those from syslink

well, i really don't know about the hard drives... having a network with only one disk in each computer to install the operating system and netdisks to save data looks really "leet" hehehehe

so looks like no one ever found a pci card with normal ethernet and wireless connections hehe, i will have to use two cards...

please view: http://www.trustedreviews.com/article.aspx?art=456

"integrated adsl modem" means that i don't need a modem, only the cable that comes from the phoneline (i think adsl comes from there... i have cable modems now) right?

the routers with a usb connection, i can only used to share a printer, right?

First of all, avoid software firewalls as much as possible if you are able to use a hardware one. It's just not worth this system resources.

You might want to check the documentation on that router. Not that it isn't possible, but I have rarely ever worked with a home router whose USB connection was actually for networked devices -- it's usually been so you can plug your PC into the router to manage it. I've only seen one that was intended to share a printer, and we never got the thing to work right. Be careful with that.

And yes, an integrated ADSL modem would allow you to plug in your phone line directly and use your ISP's DSL service. You just have to check with your ISP to make sure that this router/DSL modem is compatible with their service. It usually is.

***************
And is anyone else still annoyed by the term DSL modem?

okay, thanks

anyone got anything to say?

i still have time to see what i will buy, found another review http://reviews.designtechnica.com/review1449.html

Yeah, I'll second brichard's recommendation. Hardware firewall's work alot better and save space on the system (as well as resources which was mentioned above) as opposed to Software firewall's (such as ZoneAlarm, BlackICE, etc etc).

its strange... controlling port access in a router, what will it change? i mean... each computer has ports... which and how is the router going to close? closes the port in all the computers or what?

First of all, you don't need any wiring between computers and your router if you are going wireless. The only wire you need is between the cable modem and your router and you will only need one modem. As for your IP addressing problem, most all routers today will automatically assign addresses to your computers via DHCP and use NAT to route to your ISP. NAT also acts as a firewall in that no one knows your inside address unless you let the router do this in default, then your first computer will most likely be 192.168.0.1. Most routers come equiped with a reflexive access list which will not let any traffic into your network unless the traffic is in response to traffic originating from your network. So now you just have to worry about is cookies and trojans contacting sites outside your network.

You can set up PAT to direct certain traffic to a preselected computer if you use static addressing. A good concept of DMZ is you are logically placing that computer outside your router/firewall. That way anyone can connect to that computer through the Internet. If you are going to share the harddrives on your network, then anyone can have access to them if your DMZ computer is on. brichards99 has good advice. I hope that this helps in some way and not confuse you too bad.

A little side note:

Many ppl are recommending Linksys routers. I have set a few of those up for customers and have had bad experience with them.
These customers were using VPN connections, and the Linksys couldn't keep the wireless connections up without loosing it every now and then. (like every 10-15 minutes)
Since then (6-8 months ago) I haven't recommended the Linksys anymore, but instead been using D-Link and Netgear without any problems.

Maybe the Linksys routers are better by now, not sure?

Just thought I would mention this before you go out and buy one...