Can't connect to the net but card works

[Sera88]

I've been trying to get the wireless connection working for a couple of days now. I've learned a bunch of new things but something gets missed (or messed) in my efforts. Below are some details of my system.

Computer: IBM ThinkPad 390E
Wifi card: EDUP 54Mbps/11Mbps PCMCIA card. It has the Ralink RT2500 chip.
Linux distribution: Damn Small Linux 4.2.5
Linux kernel: 2.4.31
Wifi connection type: WEP-encrypted.

I'm using ndiswrapper for setting up the wifi connection. OK, let's start.
# ndiswrapper -i /mnt/auto/cdrom/Drivers/Rt2500.INF

Installs okay and checking with "ndiswrapper -l" it lists it (rt2500: driver installed, hardware present).

# depmod -a
# modprobe ndiswrapper

No errors here, everything goes well.
Now iwconfig lists the connection wlan0.

Then I search available Wifi access points using
# iwlist wlan0 scan
It outputs a list of APs in a second or so, so it works there flawlessly. Then I attach my WEP-encrypted AP into my wlan0 connection using
# iwconfig wlan0 essid MY_ESSID key s:MY_KEY

When I check with iwconfig, the wlan0 connection is attached with my essid.
After that I give the command
# ifconfig wlan0 up

Then
# ifconfig dhclient wlan0

Then
# ifconfig dhcpcd wlan0

After that I'm trying the command
# route
But it lists no routes.
Then I tried to enter the command
# route add default gateway 84.250.160.1
The gateway address is taken from my other Linux computer which uses LAN network (used the command route -nee). Well, it outputs this:
route: SIOC[ADD|DEL]RT: Network is unreachable

I've checked my /etc/resolv.conf file, it's identical to the one on the LAN machine, like is the /etc/network/interfaces file as well.

So the card works without a doubt as it can find the APs, but it's not connecting onto the internet. If you have any suggestions of what I should check, please tell me. I'm getting pretty desperate on this.

[Sera88]

Problem solved: don't use ifconfig dhclient wlan0 on Knoppix-based systems, but

# pump -i wlan0

That did the trick
Yay!