Home network-via-switch: 2 questions.

[Runner30]

Hi, I'm new to networking, forgive me my newbieness.
My questions are:
1.
Can I use only 1 IP adress for 2 computers?
2.
Do I have to use firewall ?

Thanks.

 

[gusgizmo]

1. yes, if you mean ip addresses assigned to you by your isp, each computer will need its own internal ip address if you want to do any normal networking. apparently windows doesnt really need an ip. . . but thats just spooky.

2. no, and i think they are really useless. just causes alot of problems. if you are really hardcore about security, i can teach you to harden your system, but i think as long as you keep your computer patched up, youll be fine. and run an antivirus.

ok, that said, can you tell me more about what you want to do with your network?

 

[Runner30]

Thanks for the reply.
It's just my mother got hold of a antique laptop, she want to access the internet for her Astrololgy hobby.
I would like our 2 computers to be independant in terms of internet traffic, don't want my comp to be always on.
I guess I can setup my own network with internal IPs use my own subnet mask( I'm only to start learning this subject).
Main system uses XP, laptop Win 98.

 

[gusgizmo]

well you have two options if you dont want your machine to always be on. you can buy or build a dedicated router for the network, or you can purchase an extra publicly addressable ip addresses from your isp, and connect your modem, laptop, and desktop all directly into the switch.

 

[axlecrusher]

A firewall is a must, more so with broadband. Don't get me started on what my connection was used for when I didn't have a firewall. You will either need two public IPs or a router.

 

[Runner30]

I'm using Cable modem ( no dialer), I have a dynamic IP .
The tech support told me I don't have to posess 2 IPs, furthermore - they told me I can connect 1 cmputer to the Cat5 connection and the other to USB connection and use both.
Is that true?

 

[gusgizmo]

umm. . . not even close. could the tech support have meant that you could hook the cable modem into one machine with usb, then the other machine would connect with cat V to the first one? and you would only need one ip for this, but as you have already said, this is not what you want to do. i think you might want to talk to someone else, this person working it sounds like he doesnt know what he is talking about.

 

[Runner30]

That's what he said - use your modem as a switch.
and you don't need static IPs.

 

[don256us]

I'm using Cable modem ( no dialer), I have a dynamic IP .
The tech support told me I don't have to posess 2 IPs, furthermore - they told me I can connect 1 cmputer to the Cat5 connection and the other to USB connection and use both.
Is that true?

Not true as written.

Connect the modem to machine A via USB and then connect machine A to machine B via cat5. Perhaps that's what they meant.

When connecting your cable modem via USB, windows will pick up on it as a network connection that can be shared. I know this first hand. I've done it and I can give you the info to do it. It is really easy too. You'll be using Internet Connection Sharing (ICS). The network card on your main machine will have to be set to 192.168.0.1. If you have Win XP, just run the wizard. You will then only have one public IP address. Both machines can browse the web. It's all good stuff.

As for a firewall, these days, you do need one. It is a good investment. Becuase your main machine will be acting as a router, you will not be able to use the free version of ZoneAlarm on it. But the Pro version is good and there are several others out there too.

Post back if you have more questions.

 

[JigPu]

Yes, using the USB and Cat5 connection will work just fine. I'd have the laptop use the USB personally, and then follow whatever instructions came with the modem. My SB-5100 was fairly easy to set up for dual operation, just needed to install the drivers on the CD onto the computer that used the USB port.

Yes, you WILL want a firewall You can harden down your security, patch windows and your AV daily, but sometimes it just isn't enough. Running a locked down system with no firewall is like having a house all set up with security cameras and motion detectors, and then leaving all your doors and windows open (...though with signs saying "this door/window does not have a buttler to greet you. please do not enter here." )

JigPu

 

[Kendan]

2. no, and i think they are really useless. just causes alot of problems. if you are really hardcore about security, i can teach you to harden your system, but i think as long as you keep your computer patched up, youll be fine. and run an antivirus.

This is as wrong as you can get Without some sort of firewall you will get the next sasser type virus You do not have to download or click anything to get it. It comes in thru a flaw in windows that might or might not be patched before the worm is out there. and if you are doing a fresh install you better put a firewall up before you go online to get all the windows updates or you will get Sasser or Blaster before you even get the updates Please explain how you would protect against Sasser or BLaster on a fresh install before you are able to get the windows updates? I include router as a firewall.





Now to answer the OP's questions:



1. No two computers can not share the same IP. Your Modem might be using DHCP or you could be getting 2 IP's from your provider. The best choice to have more than one computer on your home network is to get a router.


2. Yes it is imperative that you are using some sort of firewall even if that firewall is the built in XP firewall. This is why the best choice for #1 is a router

 

[Runner30]

Thanks for the replies!
Router -- wow this is getting out of my leage.
Maybe EDIMAX router with built in firewall will do?
I think I could get some sort of cheapo duron with Linux server and IP-table but it's ridiculous for a "network" of 1 comp and 1 mom.

My modem does use DHCP.

I guess I'll do the Laptop ->Cat V -> NIC -> USB -> modem thing.

I started the whole thing because a friend of mine told me that if I add a hub/switch between my modem and internet, I can loose the firewall.I guess he was wrong.

One last question: Can I overclock a NIC? kidding.

 

[Kendan]

Thanks for the replies!
Router -- wow this is getting out of my leage.
Maybe EDIMAX router with built in firewall will do?
I think I could get some sort of cheapo duron with Linux server and IP-table but it's ridiculous for a "network" of 1 comp and 1 mom.

My modem does use DHCP.

I guess I'll do the Laptop ->Cat V -> NIC -> USB -> modem thing.

I started the whole thing because a friend of mine told me that if I add a hub/switch between my modem and internet, I can loose the firewall.I guess he was wrong.

One last question: Can I overclock a NIC? kidding.

There is a difference between your modem using DHCP to get an IP from the provider and it doing DHCP to give all the computers at your house internal IP's thru NAT

Also you would not want to put the switch in between the modem and the internet anyways. If your ISP gives you more than one IP or your modem is doing NAT so all the computers get an internal IP then you could use it between the computers and the modem.

 

[Runner30]

Yes I mixed them.
PC1 has IP 192.168.0.1, PC2 -- 192.168.0.2, the Switch has IP of the provider and the modem 192.168.100.1
So all hackers can do is bomb the switch, wich is really not big deal.

 

[Kendan]

What model switch are you using because a normal consumer level switch will not get an IP and will not distribute ips to rigs hooked up to it. It dsounds like to me either have a router or that your cable modem is handing out the IP's What model modem are you using and what ISP?

 

[Runner30]

I'm thinking about buying EDIMAX generic router.
My modem is a Motorola SB4200 cable modem with USB+Cat 5 plugs.

 

[don256us]

Yes, using the USB and Cat5 connection will work just fine. I'd have the laptop use the USB personally, and then follow whatever instructions came with the modem. My SB-5100 was fairly easy to set up for dual operation, just needed to install the drivers on the CD onto the computer that used the USB port.

This is new for me. I didn't know you could use both ports. Thanks for the info.

 

[Kendan]

I'm thinking about buying EDIMAX generic router.
My modem is a Motorola SB4200 cable modem with USB+Cat 5 plugs.

What is the model of the switch you are using you might not need a router considering it looks like you are already behiung NAT and DHCP. OK it is not the modem handing out DHCP. is the ip of your computer start like this: 192.168...?

 

[Runner30]

Thanks for the info.

I don't have a switch or router yet.It's all in my imagination now.
Right now I have a 192.187.###.# or something external IP, and 192.168.100.1 is my modem loopback.No network yet.

I'm having trouble installing the modem driver on Win98 right now, hopefully I can solve it then use the dual option.

I'm still looking for some piece of hardware to replace any type of software firewall holding back my PC.
I wish I could afford one of those CheckPoint cards

 

[Kendan]

Yes I mixed them.
PC1 has IP 192.168.0.1, PC2 -- 192.168.0.2, the Switch has IP of the provider and the modem 192.168.100.1
So all hackers can do is bomb the switch, wich is really not big deal.

I don't have a switch or router yet.It's all in my imagination now.

It seems something is dishing out DHCP I guess it could be your modem if you do not have anything hooked up between it and the computers.


If you want to know your external IP go to www.whatismyip.com