Ever get one of those spam e-mails where the IP address is an
integer? Type it in here and it will be decoded: Enter your IP
address and your default router's IP address. Are you on the
same subnetwork? Compare your IP address and the IP address of
your DNS server(s). Are you on the same network as your DNS
server(s)? Remember, this principle is used for routing, too.
Watch what happens when you increment and decrement the number
of bits in the subnet mask (use the arrow buttons). If your ISP
has assigned your organization multiple contiguous subnets, see
if you can determine the network prefix they use for routing to
you by entering the top and bottom IP addresses you own, then
widening the network mask until they are on the same subnet!