2 IP's with one cable modem 10

[NickCat11]

Hello all,

I want to get another IP address from my ISP. First, I need to know what I need to do in order to get the new IP address to my other computer. Can it be done through the same router? For example, can I statically assign each IP address to each computer? I am new to this stuff so any help will be appreciated. Thanks in advance.

Nick

 

[vacunita]

First of all why do you want another IP address for your other computer? do you need to access it form the outside (i.e. from your office through the internet), or do you just want it to be access the internet through your cablemodem?

If the latter, then you don't need to ask your ISP for an IP address, but rather buy a router, and plug your cablemodem to it, and then your 2 PC's

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Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

 

[NickCat11]

I want to be able to access it from the outside. I already 2 home computers that are behind the same router via dhcp. I want the one computer to now have it's own separate ip. What should I do? Thanks

Nick

 

[vacunita]

If you really want to access the other computer from the outside you should consider port forwarding in your router.

In any case, to get the other computer to be seen from the outside, you'd probably need another cablemodem to connect to it, and then have it set the new IP to it directly.
by going into network properties and setting it there.

However, additional IP's maybe very expensive. Port Forwarding is the much cheaper alternative.

----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

 

[NickCat11]

Thanks for the response vacunita. It's 6.95 a month for an extra ip address from my ISP. Looks like I have to get another modem then. I was hoping I didn't have to buy any other hardware. Oh well. Thanks for your help.

Nick

 

[dilettante]

Many cable modems can handle multiple customer IP addresses.

Your cable operator raises Max CPEs by downloading new configuration profiles.

 

[NickCat11]

Ok, I did call my ISP and they said my cable modem can handle more than one ip address but they were unsure of how I can get the new ip to the other computer. Any other thoughts? Thanks in advance.

Nick

 

[Grenage]

Most modems/gateways that support more than one IP address, usually have the ability to distribute the addresses to the client machines.

Easiest thing for you to do is post your modem/gateway model here.

Carlsberg don't run I.T departments, but if they did they'd probably be more fun.

 

[NickCat11]

Motorola Surfboard SB5101 is the model of the modem. If it can distribute more than one ip how do I do so? Thanks

Nick

 

[Grenage]

Mmm, I see. It's a pure modem.

You're not going to be able to distribute two IPs through that. Your ISP should be able to supply you with the appropriate route, but sort BT ship out (2wire 1800, Siemens business routers etc) are the type of router/gateway you want.

How will having two separate modems help you. It doesn't sound like the people you spoke to at your ISP really knew what they were talking about, but that's not uncommon!

Carlsberg don't run I.T departments, but if they did they'd probably be more fun.

 

[SQLScholar]

OK - lets just confirm some techie jargon.

Do you have a router (i.e. usually connected to one or more computers via ethernet or wireless) (it has a modem built in)

or

Do you have a modem (usually connected to a single PC via usb or similar)?


If you have a router - it should be easy to have 2 IPs - or just one and port forward.

If you have a modem - you probably cant connect it to 2 PC`s. Even if you brought the second modem if they are both on the same line (phone line that is) you couldnt actually use both at the same time.

Easiest way to sort this is to buy a router.... even a wireless one costs from £40 ish. Presume a wired one would be £20-30. Then either you have the choice of port forwarding (i.e. any incomming on this port go to this PC) or getting 2 external IPs (NOTE this is not the IP of the computer) and forwarding each one to the correct Internal IP.

Hope this makes sense.

Dan

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Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind - Dr. Seuss

Computer Science is no more about computers than astronomy is about telescopes - EW Dijkstra
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[NickCat11]

I have a modem with a Belkin Pre-N Router. There are 3 pc's connected to the router. Port Forwarding is already in effect for 2 of the pc's where I created static ips, but for the third I need the seperate ip address. How can I do this with the router? Thanks in advance.

Nick

 

[Grenage]

Assuming you are hosting services on these machines, then you can simply port forward unless they are using the same ports. In which case, the second IP would be superfluous.

Failing that, you will need a router which is designed to handle multiple static addresses.

Carlsberg don't run I.T departments, but if they did they'd probably be more fun.

 

[edfair]

You should be able to use a switch behind the modem to connect 2 routers, one for each IP address. Or for that matter, you should be able to take the new machine direct to the internet through the switch without a router.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[SQLScholar]

You should be able to use a switch behind the modem to connect 2 routers,

Surely if you put on a switch the IP of the modem will be the external - and will still be a single external IP?

D

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Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind - Dr. Seuss

Computer Science is no more about computers than astronomy is about telescopes - EW Dijkstra
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[SQLScholar]

Sorry - i didnt make myself clear then (i think i went mad for a minute).

What i meant was if there is switch connected with two modems on the same line - only one will be able to be connected at any one time. If its on a separate line - thats cool.

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Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind - Dr. Seuss

Computer Science is no more about computers than astronomy is about telescopes - EW Dijkstra
----------------------------------------

 

[NickCat11]

Ok,

Thanks for all the info. I am going to buy a switch and put that behind the modem. Then I am going to attach the router to the switch and put two of my pc's behind that router. Then for the other computer I am going to run a direct line to the switch and assign that computer to the second ip address. If I went astray here, let me know. Thanks again.

Nick

 

[Grenage]

Nick,

Before you buy anything, you are ok with the fact that only one IP will be active at a time, following that theory?

I assumed you wanted two computers active on the internet, at the same time and with separate public IP addresses?

Carlsberg don't run I.T departments, but if they did they'd probably be more fun.

 

[SQLScholar]

Right...

Do you have 2 separate internet access lines or one?

Also as far as i understand it - your router(s) have the external IPs, not the PC`s themself. They will most likey have an internal IP address. Then your router points to the internal IP address of the correct PC to get the traffic for the external IP.

If you do have one line (cable yes?) then you cannot connect two routers to work on it at the same time. What you really need is a router that can deal with more then one IP.

I personally cant see how a switch will help with this other then connecting your two PC`s to a modem that may or may not (not sure as i havent checked the model) have the ability for more then One PC.

So........

If your modem can have multiple PC`s connected to it and you only have one internet access line - dont by a switch. All the switch will allow is you to connect more then one Router/computer together.

I personally think the setup you have is this

[MODEM/ROUTER] - it can have more then one PC connected at a time

[Cable internet]

[PC1]

[PC2]

If this is the case the only ways i know of to get a second IP is to get a modem/router that can cope

OR

Have a second internet access line, bridge the two with a switch. But I cant see how this will be cost effective.

I am not an expert on cable internet - although i have dealt with a couple. As far as i am aware you cannot have 2 modems on the same line at the same time.

Hope i am clear.

Dan

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Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind - Dr. Seuss

Computer Science is no more about computers than astronomy is about telescopes - EW Dijkstra
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[Maugwa]

Why not try DynDns? It's free and very well could be the answer you're looking for.