How do you perform the ANDing operation to determine the network address?

Line up the address and mask bit-for-bit and AND each pair (only 1 AND 1 = 1); the result is the network address, because ANDing zeros out every host bit.

* ANDing the address with the mask keeps the network bits and zeros the host bits. *

ANDing (Logical AND) Operation: Used to determine the network address from an IP address and subnet mask.

AND Truth Table:

Only 1 AND 1 = 1; all other combinations = 0

Example: 192.168.10.10 with mask 255.255.255.0

IP Address:    11000000.10101000.00001010.00001010
Subnet Mask:   11111111.11111111.11111111.00000000
               ────────────────────────────────────
Network Addr:  11000000.10101000.00001010.00000000
             = 192.168.10.0

Key insight: ANDing "zeros out" the host portion, leaving only the network address.

Go deeper:

• Role of the subnet mask — bitwise AND worked out (GeeksforGeeks) — a binary walk-through of ANDing an IP with its mask to get the network address.
• Logical conjunction (Wikipedia) — the AND truth table and its use in bitwise computer operations.