The same page where you put in the ports 4990 and 5000 is where you put in port 113, just on a different line. It's been a while since I used a Linksys router, so I've got to go to their site to see if they have instructions for this part (since it's an "advanced" thing, they don't support it with tech support).
Heh. Oddly, when I query their knowledge base with "How do I port forward with a Linksys router?", the response is that I used a word not allowed on their site. No idea what that means...
Ah, the
user guide has instructions on port forwarding, in detail.
The UPnP section is for Windows Universal Plug and Play, which is not something you want to enable. It's a function to enable things like automatically detecting devices on your network, but you don't want it reachable from the Internet due to security vulnerability.
The "Customized Application" field isn't really doing anything, it's just to allow you to label the forwarding function so you know why you enabled each range of ports.
The first line you could name "mIRC DCC", and the port range is as you put in, and it only uses TCP.
To add port 113 for ident, simply go to the next line, label it "ident" and put in port 113 for both "ext port" fields. This also uses only TCP.
The IP address you use should be between 192.168.1.2 and 192.168.1.99. The reason for this is that your router is probably acting as a DHCP server, meaning it is serving dynamic addresses to computers on your network. The default block of addresses it uses starts at 192.168.1.100, so your computer should be assigned an address below that, to avoid the possibility of another computer being assigned the same IP.
To configure your machine with a static IP, the first thing to do is go into the router's configuration and into the "Status" tab/screen. There you'll see the information for the "WAN" status. Write down or put into Notepad the IP's under DNS.
Now go into the Windows networking configuration (either right-click on the Network icon on the desktop, which I forget the name of in all the various Windows versions, or go to Control Panel and open Network). Select the TCP/IP configuration for the network card in your machine (make sure you pick the TCP/IP item, not just the network card) and hit Properties; the exact things you need to select will depend on the version of Windows, but I'm assuming you're using Win98.
In the dialog that follows you'll find tabs for Gateway, DNS, and IP Address (or Gateway will be on the IP Address tab in some versions). Fill in the IP address with the IP you've chosen to use, with a "subnet mask" of 255.255.255.0. In the Gateway field, put in 192.168.1.1. On the DNS tab, you'll need to put in a "hostname", which can be anything you want since it only applies to your machine, but if you ever put another machine on your network with static IP's, it ought to be unique. Then fill in the 2 or 3 DNS server IP's that you got from the router (the order isn't usually important, but should probably be added in the same order that the router had them).
On the WINS tab, you can disable WINS resolution, it's just clutter that's not needed.
Hit OK through all the menu's. Windows will do its stupid loading of drivers and probably ask for your Win98 CD, reinstall a bunch of files. It'll probably tell you that you there are new files and ask if you want to overwrite, if you've ever applied any patches from Microsoft, so you should tell it not to overwrite those files (in fact it doesn't need to copy anything; Win9x assumes that if you change something, it needs to reinstall the entire networking subsystem).
You'll then need to reboot. When you get back in, you should be able to get online (and it may even be a little faster, depending on whether the router was acting as a DNS proxy for you before, which you've now bypassed).
The second machine will still use dynamic IP addressing, as the router will continue to act as a DHCP server. You should be able to use DCC now through mIRC, and when you connect to servers, the status screen will show an ident response from you.