Internal Static IP - Tilted Forum Project Discussion Community

Jozrael · 01-04-2009, 10:08 AM

Ok, so I have two computers, a desktop and a laptop. The desktop has the primary internet connection, the laptop LANs with the desktop to be able to access the internet.

I need to be able to assign a static IP to my laptop while its on the LAN so that I can forward ports on it.

I have a Westell 2200 router.

Everytime I try to do this, I can't manage to forward the ports on the specific IP I give to my laptop (it says its not in the default subnet or something like that.

Halp please?

Vigilante · 01-04-2009, 10:29 AM

You mean the desktop shares the connection via a second RJ45 port to the laptop? It's called ICS (internet connection sharing), where the desktop shares by way of a second port to the next machine in the link, and routes data to it as requested. This can also be wireless, but I'lll treat it as wired for now.

If this is the case, LAN 1 (the router to PC), as long as it is not bridged (I hate consumer routers for this...) will be, as example, 192.168.1.1 (router) and 192.168.1.2 (PC). The next machine will be a different subnet. It has to be a different subnet, or routing issues occur.

This means laptop will be 192.168.2.2 (again, as example), and PC's RJ45 to the laptop will be 192.168.2.1. The router is the gateway for the PC, and the PC is the gateway for the laptop.

What this means is you need to kill the firewall, if running, on the PC. Then forward ports to the PC on the router. From the router, laptop traffic will appear to come from the PC, which is normal. On the incoming, however, the traffic will now pass to the PC and from there the PC will know to pass it to the laptop.

This is all theoretical, however. I have had to do this with windows before, where I had to pass traffic to and from to a router behind a PC's ICS to another subnet that contained a farm of machines crunching numbers. I had to set up manual routing entries on the PC and all kinds of fun stuff. The real kicker was this whole farm and extra PC were wireless, so all you had to do was plug in a power strip and the whole farm could run and connect immediately.

Anyways, with ICS being the pain in the ass that it is, you would be much MUCH better off buying a wired or wireless router (or switch/access point) instead of routing through the PC. The benefits are 2 fold - one, you don't get both machines hacked if someone backtracks into the port, and second you don't have to deal with ICS, and you can forward directly to the laptop.

Jozrael · 01-04-2009, 01:31 PM

Thanks

Vigilante · 01-04-2009, 02:13 PM

Hope it helps

Let me know if you run across a stumbling block during this process. I have years of fighting ICS under my belt LOL

01-04-2009, 10:08 AM	#1 (permalink)
Jozrael Junkie	Internal Static IP Ok, so I have two computers, a desktop and a laptop. The desktop has the primary internet connection, the laptop LANs with the desktop to be able to access the internet. I need to be able to assign a static IP to my laptop while its on the LAN so that I can forward ports on it. I have a Westell 2200 router. Everytime I try to do this, I can't manage to forward the ports on the specific IP I give to my laptop (it says its not in the default subnet or something like that. Halp please?

01-04-2009, 10:29 AM	#2 (permalink)
Vigilante Broken Arrow Location: US	You mean the desktop shares the connection via a second RJ45 port to the laptop? It's called ICS (internet connection sharing), where the desktop shares by way of a second port to the next machine in the link, and routes data to it as requested. This can also be wireless, but I'lll treat it as wired for now. If this is the case, LAN 1 (the router to PC), as long as it is not bridged (I hate consumer routers for this...) will be, as example, 192.168.1.1 (router) and 192.168.1.2 (PC). The next machine will be a different subnet. It has to be a different subnet, or routing issues occur. This means laptop will be 192.168.2.2 (again, as example), and PC's RJ45 to the laptop will be 192.168.2.1. The router is the gateway for the PC, and the PC is the gateway for the laptop. What this means is you need to kill the firewall, if running, on the PC. Then forward ports to the PC on the router. From the router, laptop traffic will appear to come from the PC, which is normal. On the incoming, however, the traffic will now pass to the PC and from there the PC will know to pass it to the laptop. This is all theoretical, however. I have had to do this with windows before, where I had to pass traffic to and from to a router behind a PC's ICS to another subnet that contained a farm of machines crunching numbers. I had to set up manual routing entries on the PC and all kinds of fun stuff. The real kicker was this whole farm and extra PC were wireless, so all you had to do was plug in a power strip and the whole farm could run and connect immediately. Anyways, with ICS being the pain in the ass that it is, you would be much MUCH better off buying a wired or wireless router (or switch/access point) instead of routing through the PC. The benefits are 2 fold - one, you don't get both machines hacked if someone backtracks into the port, and second you don't have to deal with ICS, and you can forward directly to the laptop. __________________ We contend that for a nation to try to tax itself into prosperity is like a man standing in a bucket and trying to lift himself up by the handle. -Winston Churchill Last edited by Vigilante; 01-04-2009 at 10:31 AM..

01-04-2009, 02:13 PM	#4 (permalink)
Vigilante Broken Arrow Location: US	Hope it helps Let me know if you run across a stumbling block during this process. I have years of fighting ICS under my belt LOL __________________ We contend that for a nation to try to tax itself into prosperity is like a man standing in a bucket and trying to lift himself up by the handle. -Winston Churchill