DCC is being screwy

[starseeker]

I've been having some difficulty getting mIRC to send things over DCC. If I get the local host info from the server, I often get Unable to Resolve Local Host (I suspect this is when a sibling is using the internet on another computer on the network). If I use the normal lookup method I can't send things at all, the connection fails. What should I do?

[Mirage]

Have you forwarded ports in your router control panel, and then set mIRC to use only those ports for DCC?

[starseeker]

Which ports would I need to forward? I've never had to forward ports for DCC transfers before.

[rubah]

DCC works like this:

Your computer sends a request to another computer, if they accept it, then they request the file from you. If there's someone else on your network, it might be that the router will try to send the back-request to them instead or just give up. This is where port forwarding comes in. You can set which ports you want to use for DCC in mIRC, then an entity such as portforward.com will instruct you in how to make this magic happen.
I've never gotten it to work.

luckily, if other people are able to send to you fine, the newer versions of mIRC have included passive dcc option, which you should use if the forwarding does nothing for you.

[Mirage]

Actually it's more like this: Your PC tells the other PC you want to send a file, and which port the other PC needs to use to get through to you. Then the other PC tries to connect to you on that port.

You need to figure out how to forward ports on your router, then you can go to mIRC options -> connect -> advanced and set the port range for DCC connections to the same range that you set in your router. You don't need to forward a lot of ports, a 4-5 should do. Any port above um, 1024 whatever it is will do, I personally use 5000-5010.

[starseeker]

Thanks, I'll try that when I've dealt with a more pressing computer issue - the on button is stuck in and can't be pressed.

[Roogle]

PortForward.com has some detailed articles about the technicalities and practicalities of port forwarding.

[starseeker]

Well I forwarded the port and it worked fine earlier. Now the problem is back with a vengeance despite nothing changing. I don't think port forwarding is the issue here. I either cannot resolve port on server mode or connect at all on normal lookup mode. It's pretty much an issue of luck whether it works or not.

[Roogle]

Did you fill in your IP address in the Local Info part of Options? Sometimes, it does not automatically resolve and that error message will come up when the field is blank.

[o_O]

What sort of router are you using? Some require a soft restart after changing the settings in order to retain them if the router loses power.

Also, are you using a software/hardware firewall? You may need to forward ports in that if you are using one.

The thing with port forwarding is that even if they are forwarded, if the remote computer can't tell that they're open, they might as well be closed. Check the following site to determine if they are actually (ostensibly) open. Just replace the number in the URL with any port inside the DCC port range (somewhere areound 1024-5000 is standard for that). A result of "Open" or "Stealth" is good, "Closed" is bad and means that they aren't forwarded.

https://www.grc.com/x/portprobe=1024

EDIT: Yes, what Roogle said too. When you forward ports, you must specify which local IP address (computer on your network) you want your router to send the data to. You can find the IP address on Windows by going to Start > Run > 'cmd /k ipconfig'.

[starseeker]

Now you mention it, sometimes the IP address doesn't come up when I use server mode. I usually just let mIRC do the filling in. Although if I swap modes, the IP address changes. But even if the things are filled in correctly I simply can't connect. I haven't had that issue for over a year.

As for the port forwarding, it's set for the right computer and all, but even with the ports closed there was never any issues and ditto the firewall. I'm just very very confused right now since it worked fine perfectly until last week.

[o_O]

Did your firewall (or router firmware) update at all? It may have switched of any form of port triggering or UPnP that you had on if you did.

What results do you get from trying the URL I provided in my last post?

[starseeker]

Well, after trying that site, it says that even the port I opened for torrenting is closed even though Azureus says it's open.

I haven't updated my firewall recently. The only thing that's changed is I got my internet package upgraded, but that only affected the modem not the router.