Multiple IPs from ISP and Linksys Router setup

[SSJpn]

I have four computers on my network sharing cable internet connection through a Linksys cable/dsl router (the purple and black one).

1) when i only had one IP address does that mean that each of my four computers shared the same IP address? when i did ipconfig it showed my IP as something like 192.168.1.10X but when i went on the internet and went to sites that checked my IP all four computers showed the same IP address.

2) Now i just purchased another IP address from ATT broadband but how do i know which computer that IP address went to? the reason i have another IP is because I want to play a game online from 2 of my computers and in order to play in the same game each computer needs a unique IP address. As of right now i have the second IP purchased but i dont know how to set it up.. do i have to do something with my router? or do i manually type in my new IP into the computer of my choice? how do i do this???

help pls i need to start gaming!!~

 

[SSJpn]

Okay i think im gonna use a different setup with a HUB and router.

Im gonna have one computer running off the HUB using one of the IPs and im gonna connect the router to the other port on the HUB and have the remaining 3 computers running off the router sharing my second IP.

Will this setup work?

where do I plug in the cable modem? into one of my computers or right into the HUB?

what is the normal/uplink button on my HUB and do i need to use it?

can i just plug my computer into spot 1 and my rounter into spot 2 of my HUB or is there a special spot assigned on the HUB that is made especially for extending the network(via my router) ?

 

[wybnormal]

A real bad idea..

The linksys router uses something called NAT(network address translation) to *share* one IP address among the PCs on the local side. The router also hands out private IPs(192.168.1.x) to the local PCs via DHCP.

If you remove the router from the equation by using a hub, you have now given all the hackers, scriptkiddies, etc an open door to your PC and/or network.

Here is one way to get around the linksys recomendations..

internet-------HUB-----router1-----LAN
|------router2-----PC

Each router gets a ISP provided IP number. The problem is the cheapo routers like the Linksys do not have a DMZ port or a way to have the router answer to multiple IPs on the WAN side.

MikeS
Find me at

http://www.packetattack.com

"The trouble with giving up civil rights is that you never get them back"

 

[SSJpn]

Instead of having the router2---PC can i just install a firewall on that PC so i dont have to buy another router? or is there another reason for having a second router besides the added security.

 

[wybnormal]

I dont trust software routers for the PC.. I have seen them break too many times when Jr installs a game(or worse) and in order to *fix* the game, they screw up the firewall settings. If you think about how stable Windows is anyways.. would you trust it?

In fact as a consultant, I refuse to use software firewalls of any kind. I have walked out on possible work because I feel a consultant has an ethical responsibilty to protect the customer from himself. And if a customer insists on doing something stupid, it's better for me in the long run to get away and let someone else take the rap when it goes to h*ll.. and it normally does. I've had a few sheepish clients call me back after the fallout has settled
::rant off::

But the answer is yes, you could put a software router..aka.. BlackIce, ZoneAlert etc on the PC, give it a real IP address and jack it into the hub coming off the DSL link.

MikeS

Find me at

http://www.packetattack.com

"The trouble with giving up civil rights is that you never get them back"

 

[SSJpn]

Thanks mike.

 

[SSJpn]

One more thing, do i just plug the cable modem into one of the ports in the HUB and it just works like that?? I thought you had to plug the cable modem into a computer and install Internet Connection Sharing (or something along those lines)and then connect that compuer to the HUB..

 

[wybnormal]

*If* you have multiple IP addresss from your ISP, then yes you can plug straight into the hub and each device that plugs into the hub normally would get a static address from the pool that the ISP gave you.

The ICS is for when you have a single IP number that you want to share among 2 or more PCs. So if you have 2 IP addresses, you can have 2 PCs on the net each with one of the two.. or take one IP, assign it to a PC with ICS (and two NICS) and fan it out..

internet--hub---Nic-PC-Nic2----hub---LAN
IP might be 204.5.5.5 LAN ip would start at 192.168.x.x

That first hub is for you to attach more then one PC using the 2nd ISP provided IP number

I wish we had better drawing tools here

MikeS
Find me at

http://www.packetattack.com

"The trouble with giving up civil rights is that you never get them back"

 

[SSJpn]

Darn i set that up in 10 minutes and powered everything up and it works like a charm. I have one more question though...

before when i had one IP and shared that through a router, whenever i went to a site that showed my IP address they all came back the same, from all 4 computers .. that makes perfect sense.

now, when i log on to those sites i have a totally different IP address from each of my 4 computers even though I am only paying for 2 IP addresses. Why is that??

But for whatever the reason is, i have no complaints at all because 4 IPs is better than 2IPs, especially when im only paying for 2.

thanks again mike!

 

[c24070]

hmmmmm....

I also use a linksys connected to a cable modem...basically the same ? the isp directs the signal to the mac address of one of the pc's.....the linksys router gives me an option to spoof the mac of the pc....it then uses DHCP to give IP
address to the local ( LAN ) devices that are not in the ISP
's address space ?

As far as your games most games give the option to use IPX
which is good for local connections...this also would allow to play at any time w/ or w/out IP running at all ?

I use this at home and it is so simple my 10 year old knows how to troubleshoot it ?

One of the main problems w/ Linksys is the throughput is poor when multiple devices are running high bandwidth applications ? ie: games