Port forwarding on a shared internet connection

So I have wireless DSL internet from 1und1 that runs via a Fritzbox 3030, and am running Windows XP. I live in a WG and there are currently four computers using the internet connection. At the moment I have a dynamic IP address, which is no good for file-sharing and also artificially inflates the webcounter stats for a website I look after.

So I want to set the computer to use a static IP address, as per the instructions given at PortForward.com. On those instructions, it says that all computers on the network should be given a static IP address, because otherwise the other users may sometimes not be able to connect to the internet.

I don't really want to go messing around with my housemates' computers, not least because I don't think they would really understand what I was doing and why. In my last WG a year ago, I distinctly recall following those precise same instructions, and none of my housemates ever complained about not being able to connect.

So my question is basically this: if I take an IP address for my own use, how often will this disrupt my housemates' connections to the internet? Will I myself sometimes not be able to connect if one of my housemates gets up earlier than me and is assigned that address?

Thanks for your help.

If you reserve a range for static addresses *on the router* then it won't ever give out those as dynamic addresses.

If on the other hand you just configure your PC to use some random address, it might screw up if the router tries to give out the same address to someone else.

The best way to do this is via the router. Most will allow you to configure the DNS server to assign a fixed address to a specific MAC address. So just choose the MAC address of your computer's NIC. Just ensure that the fixed address is not in the dynamically assigned range.

OK, thanks for that. I found the relevant page on the PortForward site and now remember setting a static address on the router last time.

Hold on a sec there...

You will still be getting a different dynamic IP address when you connect to the outside world. You can set up a static IP for your machine but that is only for the network on your side of the router. The website you look after will still see different IP addresses from you despite having a static IP on your computer itself. The website logs will just see your routers external address as your ip address, *not* your computers IP address.

Btw, Why do you think a dynamic IP address is bad for file sharing?

As others have said, you can usually reserve a range of IPs on the router that it will not give out to DHCP requests. You can set your ip to an address in this range without worrying about disrupting others. But I do not think this will help you get around the problems you are having.

Other than the skewed website stats, what problems are you having using a dynamic address?

edit: I just re-read the topic title and realised somehting.. To forward ports from the outside to your pc, yes, you will need a static ip address on your computer.. *doh*

Still dont think that will affect the website logs though (unless it is on your internal network as well )

OK, now I'm confused!

It is probably best to tell us what you want to do. Are you running a web server on your PC or just using a P2P network (which program?) for file sharing?

It's easy. Routers have a range of IP addresses which they use to give out to machines which connect and ask for one - the 'obtain an IP address automatically' setting in XP.

If you give a machine an IP address manually, make sure it's
i) unique
ii) not in the range of automatic addresses

The router automatic range will normally be 192.168.0.2-32. Check it on the config page. If so just use an IP address higher than 192.168.0.32.

Make all the other settings on the machine the same as they were when it was automatic - subnet mask, default gateway, DNS etc.

Then do your port forwarding individually i.e. don't make your machine the default DMZ machine.

If you do all this the other machines won't be affected at all.

All the common IM & sharing protocols allow you to change ports so you won't conflict.

You'll only run into problems if you have two machines which need to do something where the port can't be changed e.g. web serving.

Just uTorrent.

OK, so if other people are using a Bittorrent app you might run into problems because the router can only forward to one machine, and most clients will be set to use port 6881 (I think).

Open uTorrent, go to preferences and change the port it uses to something else, say 9888. Then forward port 9888 to your machine on the router.

Edit: if you use any IM clients like MSN Messenger you'll need to do something similar.

MSN messenger works fine here without any port forwarding (including file transfers), or am I missing something?

Depends on your router. I've had to make changes on mine. If it works leave it alone!

PS This bit is wrong. Most routers give out automatic IP addresses in a small range as above. Just give your machine an address outside the range. The highest IP address you can give for home routers is 192.168.0.254. That means there are 254-32=222 free addresses available.