Genesis doesn support dhcp "automated ip" could say
Here is one solution
http://aminet.net/package/comm/tcp/dhcp_amitcpOR
You could setup static ip, if you have windows machine in you home network, open command promt and type: IPCONFIG /ALL
If you have private network (it means that you can use static ip) you get something like this
192.168.x.x or 10.x.x.x where x is number 1-255
If you get anything else you must use DHCP
But let suppose that you have private ips
You need gateway, dns server, subnet mask and of course ip for your amiga.
Lets suppose that your PC gets ip 192.168.0.16 you could quite safety suppose that you could use ip addres like 192.168.0.101
Keep 3 first octets same 192.168.0.x and pick last wich is quite far from ip addres wich you PC use. Any number between 3-253 is acceptable