What wildcard mask should be used for the network 64.102.0.0 255.255.255.128 in OSPF?

To determine the appropriate wildcard mask for the network 64.102.0.0 with a subnet mask of 255.255.255.128, it is essential to convert the subnet mask into its corresponding wildcard mask.

The wildcard mask is calculated by taking the binary representation of the subnet mask, inverting the bits, and converting it back to decimal. The subnet mask of 255.255.255.128 can be written in binary as follows:

• 255: 11111111

• 255: 11111111

• 255: 11111111

• 128: 10000000

Inverting this binary representation results in:

• 0: 00000000

• 0: 00000000

• 0: 00000000

• 127: 01111111

This gives the binary wildcard mask as 00000000.00000000.00000000.01111111, which equals the decimal value of 0.0.0.127.

This wildcard mask indicates that the first 25 bits (since 255.255.255.128 allows for 25 bits of the address) of the address are fixed, while the