My problem is I forwarded the port 6881 in my linksys router (I don't know the model # off hand). It works fine in windows, but in linux it says that it is not forwarded. my local ip stays the same so it should still work. I am basically running a fresh install of slackware 10.2. I am connected the the router with a wireless card that is a dlink dwl-g650 using the madwifi drivers.

I'm also wondering if I have setup the card right, I can connect to the internet and everything seems fine, but I'm wondering if I may have done something wrong that would conflict with something. I installed the madwifi drivers, and I run: dhcpcd ath0 -B, in the madwifi site it says to run dhclient ath0 but this does not work for me. Is there any disadvantage to using dhcpcd? thanks.

dhcpcd and dhclient are two different dhcp clients that do the same thing.

I use dhcpcd myself, but different distros will install one or the other. I wouldn't worry about it.

As for your problem, what is getting forwarded on port 6881? Do you have something on the Linux box listening there? If there is nothing there to accept the packets then they will be refused by the kernel...

Do you have iptables firewall on your slackware?

Is this for bittorrent? If so fire up your client, and it should see the packets (if configured to listen on port 6881)