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

 

[NickCat11]

Ok,

Plank you are right. I have one internet line that goes into the modem and then I have a line from the modem to my belkin router in which I currently have 3 pc's hooked up to it. My modem has another spot in it for a usb internet connection. Can this be used to run the second ip address. Or, if not, what brand of router supports multiple ip's? Thanks again

Nick

 

[edfair]

I haven't done it with a cable modem. But the commercial stuff I have worked with have things addressed to 5 different IP addresses all coming out on one cat5 port. And using a switch I've been able to get 2 routers connected via 2 different firewalls. One through a Cisco PXE and the other through a Sonicwall.
So it is a matter of two different packets coming down the line at different times. If it was one address it eventually sorted out that it went one way and if the other address it went the other way.
I am assuming, since your ISP will give you a second address that you should be able to see and use either at any time and any conflicts will sort themselves out in the normal ethernet manner.
Don't let the mention of the firewalls throw you. They were in the circuit to do routing of some traffic between a windows network and a unix network while keeping parts of the same network totally separate. If you've seen a network layout and the cloud representing the internet, we basically created parallel clouds. Common cable to a switch, each switch leg to a firewall and router and each router into a switch and the common back into local network.
This held true for both ends of the clouds.

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

 

[dglienna]

Most cable modems only work on either USB or Ethernet. That's why you have to shutdown to switch. They won't both work at once. Only the first one connected after you boot.

-David
2006 & 2007 Microsoft Most Valuable Professional (MVP)
2006 Dell Certified System Professional (CSP)

 

[phillid2]

I would rather save the $6.95 a month and use port forwarding.

Don Phillips

http://worthingtonengineering.com

 

[tlcscousin]

You can connect a hub so it would go modem to hub then hub to one pc and hub to router for other pc's.The one pc would get an IP from cable modem and router would get the other IP address.

 

[dglienna]

but not a cable modem, with USB and Ethernet ports

-David
2006 & 2007 Microsoft Most Valuable Professional (MVP)
2006 Dell Certified System Professional (CSP)

 

[edfair]

The choice would be switch rather than hub. Hubs repeat everything they get to everybody. Switches figure out where the traffic should go.
I had forgotten that I had set up a Goldmine (contact software) server like this. Connected it to the internet through a switch and another switch port went to a firewall/router for the inhouse network. The Goldmine used one IP address and the router another.

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

 

[SQLScholar]

You can connect a hub so it would go modem to hub then hub to one pc and hub to router for other pc's.The one pc would get an IP from cable modem and router would get the other IP address.

Really dont think you can run 2 modems/routers on the same cable line. Check with your supplier!

----------------------------------------
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
----------------------------------------

 

[gpalmer711]

There seems to be some mis-information being posted here and really the ISP should have been in a position to advise you on this, however as is becoming more frequent Customer Support centers don't know their @$$ from their elbow. Perhaps this is just an indicator of how rare a situation this is for home users.

If the modem can handle more than 1 IP address, which you say that it can you should be fine. See

http://www.dslwebserver.com/main/fr...IP-addresses-with-Router-and-Private-LAN.html

for a diagram of what you are trying to do.

What might be better is if you can let us know what you are trying to accomplish with the 2 IP addresses and we may be able to inform you or easier/cheaper ways of doing it.



Greg Palmer
Freeware Utilities for Windows Administrators.

http://www.palmersoft.co.uk

 

[NickCat11]

I just wanted to thank everyone for their help with this question. Gpalmer, I am setting up my own ftp server and possibly down the line, a web server. I was advised to use a seperate ip for either one of these. I think I have all the info I need to complete this successfully, thanks to you guys. Thanks again everyone!

Nick

 

[edfair]

Good link Greg.

 

[Serbtastic]

Assuming neither of the 2 pcs behind the router is running ftp/http, you can use port forwarding for these services through your router, and save yourself the cost of an additional IP.

 

[NickCat11]

Serb,

So if I want to host my own web site, I don't need an additional ip for this?

Nick

 

[NickCat11]

Serb,

I was led to believe that if I wanted to host my own web site, then I would need an additional ip address to keep things separate. Is that incorrect information? Thanks

Nick

 

[gpalmer711]

Yes it is incorrect. As a default FTP will use port 21, likewise Web Servers use ports 80 and 8080 (unless you are using https, in which case there are additional ports).

So here is your situation, 1 Cable Modem with public ip connected to a single router. Router connects to 3 computers. Computer 1 Runs Web server, Computer 2 runs FTP server, Computer 3is for internet access.

On router forward ports 80 and 8080 to computer 1 and forward port 21 to Computer 2.

And thats it.

Of course you could run both the web server and ftp on the same machine and that would work fine as well.

Greg Palmer
Freeware Utilities for Windows Administrators.

http://www.palmersoft.co.uk

 

[NickCat11]

gpalmer,

Thanks for the clarification there. So when exactly would you need an additional ip address, just out of curiosity? Thanks

Nick

 

[Grenage]

When you have you wish to run the same service, or run services using the same ports, on different devices/computers.

There are also times where you might wish to, due to routing or preference; etc. It doesn't look like either of these will apply in your case.

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

 

[gbaughma]

You would need additional IP addresses if you were:

Doing load-balanced hosting
Separate web servers
etc.

Each computer needs it's own IP address. *however*, they don't have to be public addresses. If you get additional addresses from your cable modem provider, those are public addresses. You might want to do that, for example, if you wanted to have two machines at home, and be able to remote desktop into either of them, or have two separate web servers running, etc.

What you are doing is "splitting" the traffic when you are using port forwarding.....


INCOMING PUBLIC IP ADDY ------> PORT 80 ------> Web Server
PORT 21 ------> FTP Server

etc.



Just my 2¢
-There once was a man from Peru
Who wanted to write a Haiku
but...

--Greg

http://parallel.tzo.com