In most networks, the gateway is (almost) always x.x.x.1 (usually it's the IP of the router or something linked to the next network, like the Internet for example. Broadcast packets always go on the upper limit of the subnet (usually 255). From the numbers you have above, it looks like you listed the IP address you had, the subnet mask, and the gateway. So with Knoppix (a Debian-like distro) your /etc/network/interfaces would look like (I think):
iface eth0 inet dhcp
It looks like the gateway is on a different subnet, but try that and see if it works...