LPM longest prefex match

Subnet Calculation:

IP Address:	205.215.175.94	11001101.11010111.10101111.01011110
Subnet Mask:	240.0.0.0	11110000.00000000.00000000.00000000
Wildcard Mask:	15.255.255.255	00001111.11111111.11111111.11111111
Network Address:	192.0.0.0/4	11000000.00000000.00000000.00000000 (Class C)
Broadcast Address:	207.255.255.255	11001111.11111111.11111111.11111111
First Host:	192.0.0.1	11000000.00000000.00000000.00000001
Last Host:	207.255.255.254	11001111.11111111.11111111.11111110

Row 1: Network 10.0.0.0 / 255.255.255.0
Row 2: Network 10.0.0.0 / 255.255.0.0
Row 3: Network 10.0.0.0 / 255.0.0.0

Then, when a packet comes in, destined to, say, 10.10.10.10, the router will start at the top of the routing table, performing a bitwise AND between the destination IP and the netmask of the route in that table row.

Key = SubnetId = IP & Mask;