Connection frustration

[Lithl]

Netstat says I'm listening on 1802. Windows Firewall says 1802 is open. My router configuration says 1802 is being forwarded to me.

But according to PC Flank, 1802 is closed.

I am stumped, honestly. The weird thing is I recall getting a successful connection with my friend on the demo before I purchased my license, and I hadn't changed any of my network settings since. Today is the first I've messed with them, trying to get the connection to work.

[joshuha]

My router configuration says 1802 is being forwarded to me.


Is your router using DHCP? Are you sure that the 1802 forwarded internal IP is the same as your computer IP?

[Griogre]

Did you test to see if the port was open while running the FG server?

[Lithl]

Is your router using DHCP?"Use Router as DHCP Server" is checked, if that's what you mean. (NetGear WPN824v2)


Are you sure that the 1802 forwarded internal IP is the same as your computer IP?The router is forwarding to the "Internal" address listed on the FG launcher (which is the same as the IPv4 address from ipconfig)


Did you test to see if the port was open while running the FG server?Yes, and I also tested with the connection test in the FG launcher.

[Griogre]

If you are using DHCP that means your local IP address is being assigned dynamically and is subject to change. This can mean that if the IP address ever changes you are port forwarding to the wrong local IP address. This is most likely to happen when the router resets or if you have fewer addresses available for the router to use than you have devices connected to the router. Typically most leases on local IP addresses are renewed, assuming adequate available numbers, so a problem like this might not show up for a long time.

You should make the local IP address of the computer you are using as a server a static one so it always has the same number. Most routers allow this.

[Lithl]

Aside from the fact that my local IP address hasn't changed for several months, how would I go about doing that? I tried setting myself to a static IP earlier when trying to resolve the problem on my own, but that ended up cutting off my internet all together, so I assume I did it wrong.

[Griogre]

It's router dependant, so I can't really tell you off hand. It's probably in the same area as settings for the DHCP server. You may be able to lock an local IP address to a specific MAC address which would do the same thing.

[Hamish]

Just a thought... does your router have a built-in firewall as well? Have you opened up port 1802 on that one?

[Griogre]

As Hamish says, pretty much every piece of hardware between your router and computer has a firewall. You modem, router, switch, ect.

[Lithl]

I can't find any firewall settings in the router configuration, and the gateway computer (Fedora 9) says its firewall is turned off. Modifying the iptables on the gateway brought down the internet throughout the house, so obviously I did something wrong there if I was supposed to do anything at all.

The router and gateway are the only bits of hardware between me and the internet.

[Dershem]

Hamachi

https://secure.logmein.com/products/hamachi/vpn.asp?lang=en

Solved all my connection problems. As long as everyone is willing to run it.

[Griogre]

I can't find any firewall settings in the router configuration, and the gateway computer (Fedora 9) says its firewall is turned off. Modifying the iptables on the gateway brought down the internet throughout the house, so obviously I did something wrong there if I was supposed to do anything at all.

The router and gateway are the only bits of hardware between me and the internet.
Bear in mind if the firewall is off that often means ports are locked and not fowarding. I'm not sure about a Linex firewall though. For most Windows firewalls being off doesn't mean it lets everything through, just all port configurations are frozen and probably forwarding doesn't work. Thus 1802, upless you opened it prior to setting off the firewall, is not open (and never will be open until you cut the firewall back on and open it). You never want to turn a firewall off unless you have multiple ones on one device/computer. Windows Update has been know to cut the default firewall back on after an update to it.

If you are not using the default firewall on your server computer you should also check to see if you have more than one software firewall on. Having more than one usually screws things up.

[Zeus]

I'll add my two pence worth. If your running Fedora9 then for iptables the following should open and forward port 1802 to your server's IP (assuming its statically assigned.




iptables -t NAT -A prerouting_wan -p tcp --dport 1802 -j DNAT --to <replace with ip of your server>:1802
iptables -A forwarding_wan -p tcp --dport 1802 -d <replace with ip of your server> -j ACCEPT



You also need to restart iptables, /etc/init.d/iptables.

In addition to ensuring iptables is configured to open the port and forward the traffic you may also have SELinux running. SELinux is a policy based security layer (sort of like Vista's UAC) which runs in enforce mode by default, try temporarily disabling it (Security Level & Firewall under System->Administration menu) and see if that makes any difference. If it does you may want to put SELinux into permissive mode or keep it disabled outright.

I run Fedora and disable SELinux along with UAC on my Vista systems, too much pain for one man to bare. I still have a firewall but one wall is enough for me.