Psy1280 Sorry for all the technicalities. It is hard to tell what people on this forum know and do not know. It seems like @Kring has provided you with a solution, at least for when you are at home.
FWIW, DHCP is the Dynamic Host Configuration Protocol and is generally used by computers when they connect to a network to obtain networking information (IP address, gateway, etc). This is used to avoid two computers using the same IP address because if they do then you'll get severe networking issues. Just imagine that you try to send a letter to a certain address and there are two houses with the same address. Who to deliver the letter to? So computers need to "negotiate" their network or IP addresses and DHCP is used for that. So at least one computer needs to be in charge and in case of only an ASIAir and an iPad, none is. So that could give problems and the default option is for neither to assume an IP address.
This essentially means that no communication between the two can take place unless either one component starts telling the other(s) when IP address to use (this is the ethernet switch approach I proposed) OR you manually assign unique IP addresses to each component. This is fairly easy with the iPad but quite hard with the ASIAir if you are not familiar with Linux.
I hope this explains a bit what I tried to say in a few sentences before š
