Newb TCP/IP question

Okay, I’m trying to start a small Diablo 2 game for a couple of friends. I’d like to connect via TCP/IP, primarily so that we can use whatever names we want (rather than having to find one that isn’t already taken). First off, is there any big disadvantage to TCP/IP that I should be aware of?

If not, I’m having trouble getting it to work. I connect to the Net over an Earthlink DSL connection, with a Linksys router between me and the wall (leftover from a LAN I used to run). I can connect via TCP/IP to other peoples’ Diablo 2 games, but nobody can seem to connect to mine. When I go into the XP network manager, I see two connections listed under Broadband: Earthlink and WinPoET. Both are listed as “disconnected.” If I tell one of these to connect, the connection attempt fails.

There are three under LAN or High-Speed Internet: 1394 Connection, 1394 Connection 2, and Local Area Connection 3, all listed as “enabled.” None of the connections shows traffic except for LAN #3. The IP for LAN #3 is the same as the one I get reported to me by Diablo 2 and by ipconfig in the command window. So I assume that’s the correct IP, right? If so, why can’t people connect? Do I need to somehow configure my router to accept incoming connections or something? I’ve never had any problem playing games over the Net before. And Battle.net works perfectly for me, as does TCP/IP if someone else is hosting. Help!

Your PC is fine. Most everything is handled by the router.

What you need to do is forward ports 4000 and 6112-6119 from your router to the PC. Then you can host games.

The manual for the router or help will tell you how to do this.

Thanks, XPav. I looked that stuff up. My ISP uses dynamic IP addresses, so it seems like the only way to get this to work is to reset the forwarding anytime my IP changes, right? (Because I have to specify the port, and the IP the port gets forwarded to.) My router also allows something called “DMZ Hosting” that, according to the manual, exposes my entire computer (which I take to mean, all ports) to the Net. Is that incredibly stupid and unsafe for me to do?

I would stay away from the DMZ option unless you really had to. The only times I’ve needed to use anything like that involved Netmeeting (which uses a range of high ports, so you can’t just open certain ports). You can either statically assign your PC and then configure your router to route the ports XPav mentioned to that IP, or just put in the IP that your PC is currently using. If you have a small network, or that is the only PC on the network, it’s unlikely that the IP will change.

I’m trying to understand. My ISP issues me a dynamic IP address every time I log into their system (like when I reboot my computer). My understanding–which is very limited–is that the router also assigns IPs to the individual computers on my LAN (there’s only one right now). I think what you are saying is, I can tell my router to always give my PC the same LAN IP (no matter what IP I get from the Net), and to always forward the magic ports to that LAN IP that I specified. If I reboot my computer, I have to tell my friends what my new dynamic Net IP is, but my internal LAN IP stays the same so I don’t have to mess with the forwarding, even though my external IP changed. Is that all correct?

If so, awesome, and thanks. I can’t figure out how to assign a static LAN IP to my PC (nothing about it in the manual), but I’ll keep poking around.

Nail - Head - Hammer, and you just hit it straight on. Hopefully you’ll be hacking away in no time.

As for the static IP stuff on your PC stuff, you’re right, thats not in the router manual, because you just do that on your PC (shoulda mentioned that in the last post). You don’t have to disable DHCP on the router, but it sometimes help.

The important part is to pick an IP address in the same subnet. So if your router has the internal (external is the one assigned by the ISP) address 192.168.0.100, just set your PC to static IP to 192.168.0.50 or something, and make the subnet on the PC 255.255.255.0, the gateway on the PC 192.168.0.100 (this is how it gets out to the internet) and the 2 DNS servers the values that your ISP has given you. (Or you can get those from Windows if those are DHCPed also).

Then setup the port forwarding with the IP address you picked for your PC.

Nail - Head - Hammer, and you just hit it straight on. Hopefully you’ll be hacking away in no time.

As for the static IP stuff on your PC stuff, you’re right, thats not in the router manual, because you just do that on your PC (shoulda mentioned that in the last post). You don’t have to disable DHCP on the router, but it sometimes help.

The important part is to pick an IP address in the same subnet. So if your router has the internal (external is the one assigned by the ISP) address 192.168.0.100, just set your PC to static IP to 192.168.0.50 or something, and make the subnet on the PC 255.255.255.0, the gateway on the PC 192.168.0.100 (this is how it gets out to the internet) and the 2 DNS servers the values that your ISP has given you. (Or you can get those from Windows if those are DHCPed also).

Then setup the port forwarding with the IP address you picked for your PC.[/quote]

One other thing – Denny just started another conversation about Dynamic IP addresses over in another thread. There are services – like dyndns.org – that allow you to get a static domain name assigned to your dynamic IP address. I don’t play Diablo II, but if Diablo supports connections via domain names, it means your friends could connect to rywill.no-ip.com every time, rather than an ever-changing IP address.

XPav’s instructions for the Linksys are right on.

Aleck

This all worked and I am now able to host my game. Thanks for all your help, guys. This board rulez.