I'm learning subnetting at the moment and I'm unsure whether this is considered a valid IP address.

My teacher asserts that this is invalid because it is a broadcast address of one of the networks within a subnet, but my instincts tell me that the broadcast won't be until at the end of the first subnet network.

2 Answers 2


It is a perfectly valid IP address on the network The host component of the address 101.11111111 is neither all zeros, or all ones.

$ ipcalc
Address:         10010110.00010000.00000 101.11111111
Netmask: = 21   11111111.11111111.11111 000.00000000
Wildcard:            00000000.00000000.00000 111.11111111
Network:        10010110.00010000.00000 000.00000000
HostMin:           10010110.00010000.00000 000.00000001
HostMax:         10010110.00010000.00000 111.11111110
Broadcast:         10010110.00010000.00000 111.11111111
Hosts/Net: 2046

You are correct, is the broadcast address for the subnet. is a valid IP for a host on that subnet.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.