WOT: need computer help...., need to assign an IP address to a particular computer.... Options

[scottb]

on my network.

i have a linksys BEFSR41 and have 2 IP addresses through comcast (at least that is what they tell me).

i need to do the following:

find out my IP addresses

assign one of these addresses to my wifes work computer, and let the rest of the house use the other.


i have messed around within the router but as i don't know my ip addresses. i do an ipconfig and only get one ip address.

so any suggestions oh wise ones? my wife an i both work for the same company and the security system is such that only one log in per ip address is allowed (hence the need for 2).

hope this is clear enough....

thanks,

scott

[KaptKaos]

www.ipchicken.com will show you the IP address you are presenting to the outside world. This is one of the two public IPs that you have. Most residential ISPs do not give static IP addresses so this is a little different. Please confirm that you are getting two static IPs from your ISP.

If that is the case, you will need to statically assign one to the public port on your router. The other will need to be setup as a NAT (Network Address Translation) on your router and point to the Private IP address of your wife's PC.

In your router you will need to specify that you are using static internal addressing. Do not use 192.168.1.X as you local private network. Use 192.168.100.X with 255.255.255.0 as the subnet mask (full class C). You don't want to use the 192.168.1.X because some corporate networks use that too and a VPN connection may not work if that is the case.

On each PC you will need to statically assign IP addresses to each PC and the one on your wife's PC will need to correspond to that public IP that you NAT at the router. You PC can be any IP as long as its not the same as the wife's.

I hope this helps. PM me if you need more help. Something still doesn't seem right with this, but good luck anyways! (IMG:style_emoticons/default/drunk.gif)

[effutuo101]

You have two IP addresses and want one dedicated to your wifes puter and the other to go through a wireless or wired router. Some providers require you to register a single computer to each IP. You will then have to log into your router, set IP address, clone the MAC address so the router will register on the network, you can build anything out from there. Class C is a good way to go. If you have a network resource (printer or print server) you can put a hard address on that (easiest) and attach it to the network. Good luck. Not hard to do. You also want to have some security on your wireless. Either MAC address filtering or WEP security ( you will have to put this WEP security on your other computers.

[Dr. Roger]

your wireless router has something called DHCP.
That means that you can share one IP with a bunch of people.

Why does your wife need a dedicated IP? Work?
I doubt your wife needs a dedicated IP for work as most corporations use a RSA token to pass through a firewall these days. That method of security is only worried about what key is used in conjunction with a PIN to access the corporations website.

Does this sound right?

If she really needs a dedicated IP you will need to hook up a hub just after the comcast modem, and splice off her dedicated IP connection separate from the router, and the other cable will go to your wireless router to share with the rest of the house.

Anyone know of a different way besides two cable modems? =)

Roger

[Sarastro]

Anyone know of a different way besides two cable modems? =)

I sure cannot think of another way. Two IP addresses should require two modems and two gateways. I can think of no residential application where this would be necessary. Are you sure you are not confusing the WAN IP address you receive from your ISP with the Local Area Network (LAN) addresses assigned by your router? Both of these are often referred to as Internet Protocal (IP) addresses, but they are vastly different in their application.

If you can explain exactly your ultimate objective, perhaps we can lead you in the right direction.

[scottb]

roger, you are correct that we use rsa keys to log in to the secure company server. however when we both try to log in, the first one can get through but the second is not recognized and is unable to connect. when i spoke with the it guru's they told me that multiple log ins through a single IP address are not allowed and they have the same problem when checking rsa key connections on their single dsl line.

my first thought was that i need 2 modems which i will do but the good people at comcast say if i use 2 modems then i have to pay for 2 internet accounts. whereas they were able to assign me a second IP address for $4 per month.

i am certain i am mixing acronyms and misusing jargon so i really appreciate the help. i know just enough to be dangerous. the final goal is to set up the home network in a way that will allow both the wife and i to work from home simultaneously.

thanks in advance.

scott

[Sarastro]

Scott,

Before you spend any money on additional equipment or services, check with these gurus and ask about your using an onion router or TOR. This is free software that might effectively mask your real IP address by temporarily allowing you to use someone else's. (This is a trick that file shares use to hide from the RIAA.) TOR may solve the problem of a single IP address and concurrent logins.

Of course it may not work but it costs nothing to ask.

You might just have to spend the money the achieve your goals.

[Richard Casto]

I am not as up on this as I used to be. I suspect that your ISP is giving you two dynamic IPs. I think what I would try would be to obtain a second router and a switch. Connect the switch to the cable modem. Plug the old and new router into the switch. Each router will now be able to get an IP via DHCP from your ISP. If you have static IP, then you need to setup each router with each IP on the WAN side.

On your LAN side you probably would need to continue to use NAT. Each LAN will be independent of each other and can't directly talk to each outer without routing out through each router. This means that you probably can't easily do things like share folders between your two PCs. You might be able to put in a second NIC in each machine and have them both on a shared network, but that is getting really complicated.

If the RSA security stuff doesn't like the NAT via your wifes router, then you could bypass the new router and have her plug directly into the switch that is connected to the cable modem. The problem here is that she will not have any firewall protection that the router would have provided. But I am guessing you can make this work as described above.

Someone with more experience than me, please validate this approach before he runs off and buys a second router and switch. (IMG:style_emoticons/default/biggrin.gif)

[KaptKaos]

I'll say this again. Confirm that your ISP is giving you two STATIC IPs. If they are not static, then everything else we try to do is a waste of time.

Your router sits between your DSL/Cable modem and proxies your PCs to the internet. Right now, they both are using the same PUBLIC IP address. If you want both PCs to access the corporate network, they need to have dedicated PUBLIC IP addresses to proxy via the router. You need to program the router to do this via NAT. It should be able to do it, but it's useless to try if you don't have STATIC IPs from the ISP. If the ISP gives you dynamic IP addresses, then they may change over time, and that doesn't help you.

You could remove the router and connect the DSL/Cable Modem to the switch that the PCs connect to and allow the PCs to get IPs from the ISP via DHCP. This would work, but leave your PCs open on the public Internet, which is a bad idea.

[scottb]

you guys are making my brain hurt! (IMG:style_emoticons/default/blink.gif)

i have a switch and i have a couple of routers. i will try the switch then 2 router approach. i will also contact comcast to see if i have 2 static ip addresses or 2 dynamic.

i all else fails, i suppose i could fall back on 2 modems and spring for a second internet account.

cheers,

scott

[Dr. Roger]

before i do anything, try this....

cable comes into modem
modem ethernet cable goes into switch/hub
one ehternet cable goes from swithc/hub into wifes laptop and supplies one IP address.
other ethernet cable goes from anothe rport from switch/hub into wireless router which supplies other assigned IP address which is setup through the router.

it can't hurt to try.

[Sarastro]

Wow, I've set up and maintained quite a few networks and you guys are confusing the hell out of me, poor Scot.


There is some misinformation here about static addresses. Most of these "static" addresses that ISPs issue are not constantly connected static connections. A constantly connected static connection is needed to find your WAN IP address from the outside internet (if you have that need). What ISP generally provide are unchanging IP addresses which are constantly dropped by the ISPs NAT servers when not in use. The simple solution is to constantly ping from your machine to anywhere else, keeping the internet connection active and available for connections from the outside. There are plenty of free clients available to do this for you. There is also a nifty little free program called Hamachi to do this all for you, and you do not need a static address to make it work. There are other work arounds to the static IP requirement but they are out of the scope of our requirements.

I seriously doubt you really need a static address, you just need an independent IP address for your logon. If you do, you'll need to go back to the gurus at work for an application explanation.

Part of the major problem here is one of nomenclature. Modems can be routers, routers always include hubs but may include modems but not unnecessarily and it is possible to hook a computer directly to an ISP's modem without using a router at all (not really recommended).

I recommend you get back with the guys are work and let them help you out.

[scottb]

I recommend you get back with the guys are work and let them help you out.

our it department is farmed out to another company. they really could care less. i do know a couple of the guys who are on site and will pester them if the suggestions provided don't work.

i will give rogers approach a try. i do have stand alone modems, stand alone routers (linksys x2) and a linksys switch hub. maybe i can pull this off with all this crap.

if nothing else, i will get a second internet account and run a modem for my wifes work computer and another for the rest of the house. so i am out $42/month, oh well.

i really do appreciate all the input. i will advise the outcome once the wife is done with work and i can disconnect everything!

after i do this, i am going to get a job with geek squad!

cheers,

scott

[Richard Casto]

Wow, I've set up and maintained quite a few networks and you guys are confusing the hell out of me, poor Scot.

Thats OK, your reply confused me as well. (IMG:style_emoticons/default/confused24.gif)

Scott,

Roger's idea is pretty much the same as one I suggested and I suspect it will work. Just wanted to point out again that directly connecting to the hub/switch does leave that PC more exposed to attack. If it does work, consider using the second router for your wife.

I also suspect the static vs. dynamic IP is a red herring. That it will probably work fine either way.

Richard

[KaptKaos]

The static IP issue is not a red herring. It requires a totally different setup from what else has been offered AND the other solutions leave the PC that is not behind the router totally exposed to the internet.

[Dr. Roger]

cool then.

so use both routers and you'll be protected. =)

[scottb]

ok, tried the following:

modem to switch

wife computer to switch

router to switch

router to rest of house

wife and i could still not log on to the secure vpn network at the same time. for those in the know about these systems, we received a 403 error indicating that client was not recognized.

next will be to try putting a router between the switch and wifes computer. also need to call comcast and find out if i have dynamic or static ip addresses.

thanks for all the input.

scott

[Richard Casto]

The static IP issue is not a red herring. It requires a totally different setup from what else has been offered AND the other solutions leave the PC that is not behind the router totally exposed to the internet.

I am not trying to be argumentative at all, but why again would he need static IP addresses? I am guessing that this has worked previously for him with just a single IP (that is most likely dynamic). Also, I believe that many users of this type of remote access systems are people who travel (sales, etc.) and have no way of getting a static IP when on the road at a remote location. This also applies to any remote person who may have to use dialup.

[Richard Casto]

A few things to check. When you had both PCs connected, can you verify that you were actually getting two IP addresses from your ISP? I think you can check this by logging into your router and seeing what IP it is using on the WAN side. You would check this on your wife's PC by doing something like an "ipconfig /all" at a command prompt. I would think that both would be in the same IP range, have the same subnet mask and same default gateway. If you are both getting IPs from your ISP, you would then need to make sure that you both can access the internet at the same time.

This is grasping at straws here, but I wonder if maybe the ISP doesn't have you setup for the second IP?? That maybe the router starts up, gets an IP via DCHP. You login and it works. Then you boot up your wifes PC, it gets an IP via DHCP (but the ISP knows you only should get one, so they revoke the reservation for the first one used by the router) then she can get in, but then your connection is toast?

[KaptKaos]

The static IP issue is not a red herring. It requires a totally different setup from what else has been offered AND the other solutions leave the PC that is not behind the router totally exposed to the internet.

I am not trying to be argumentative at all, but why again would he need static IP addresses?

IF you are running a router and require that the two PCs on the LAN behind the router present different public IP addresses to the internet, then you need to NAT them. It doesn't make sense to do all of the work to setup a NAT if those addresses are dynamic and can change.

I am guessing that this has worked previously for him with just a single IP (that is most likely dynamic). Also, I believe that many users of this type of remote access systems are people who travel (sales, etc.) and have no way of getting a static IP when on the road at a remote location. This also applies to any remote person who may have to use dialup.

I don't know if it has worked with 2 PCs in the past, however, now he's trying to get two PCs to connect via a VPN to a corporate network that requires unique IP addresses from the source. If you stick them behind a router, that router will grab one IP from the DHCP server and port translate the requests thereby giving all PCs behind the router the same public IP address.