What wildcard mask is needed for the OSPF network statement for 198.19.0.0 255.255.252.0?

The correct wildcard mask for the OSPF network statement associated with an IP address of 198.19.0.0 and a subnet mask of 255.255.252.0 is indeed 0.0.3.255.

To understand why this is the case, it is essential to first recognize how wildcard masks are calculated. A wildcard mask is essentially the inverse of a subnet mask. That means each bit in the subnet mask that is set to '1' becomes '0' in the wildcard mask, and each '0' in the subnet mask becomes '1' in the wildcard mask.

Starting with the given subnet mask of 255.255.252.0, we can break it down into binary:

• 255 = 11111111

• 255 = 11111111

• 252 = 11111100

• 0 = 00000000

When we invert this binary representation to find the wildcard mask:

• 255 = 0 (inverted)

• 255 = 0 (inverted)

• 252 = 3 (inverted) [11111100 becomes 00000011]

• 0 = 255 (inverted)

Thus, the wildcard