Back to the basics- ARP

I was using  wireshark and noticed all the the ARP requests going thru my network. I knew what the protocol did and the basic function but I for got how it works with the Default Gateway to resolve MAC addresses.So I did a lil readimg and here is a little write up on ARP that helped me out.

help with subnetting

Most of the time I only have to do subnetting for smaller networks maybe up to something like /20 but if i need a handy guide for study or just for reference here is a cool one form Cisco.

P Routing Host and Subnet Quantities