the following command should work

ipconfig -a

if that's not working, maybe it's not in your path, try

/sbin/ipconfig -a

or

/usr/sbin/ipconfig -a

or find it in your path. Try

which ipconfig

if you have iproute2 (debian actually calls it iproute) installed, then

ip addr list

will work as well

In either case you'll have to figure out which is your wireless (perhaps with dmesg or lspci) and which is your wired connection if you have more than one nic, but that's not usually hard -- the results contain more than the mac addresses too, but they're easily parseable to find what you're looking for.

If you have SuSE, open the YaST network card module and select "change" if you have already configured your device. Look in the device column. You should see something like eth-id- followed by your address.